ChatGPT answers, unedited

For a mid-market retailer focused specifically on paid search competitive intelligence, I’d shortlist SpyFu and Semrush.

• spyfu.com — probably the closest fit if your main needs are competitor keyword spend estimates + historical ad-copy changes. Its PPC research includes estimated spend/clicks, competitor keywords, and an Ad History database showing how competitors' ads have changed over time. SpyFu SpyFu
• semrush.com — better if you want competitive PPC intelligence alongside broader SEO/marketing research. It provides estimated traffic cost/spend at the keyword level, paid-keyword changes, competitor ads, and historical advertising trends. Semrush Semrush

For your specific use case

One important caveat: neither tool knows a competitor's actual Google Ads spend. Spend/“traffic cost” figures are modeled estimates based on observed keywords, traffic, CPCs, positions, etc.; Semrush explicitly describes its figure as an estimated cost. Semrush Semrush

My practical pick: If you're primarily a paid-search manager and want to answer “What are they bidding on, roughly how much are they investing, and what messaging are they changing?”, I'd trial SpyFu first. If your team already uses Semrush for SEO or wants one broader competitive-intelligence platform, Semrush is the more consolidated choice. SpyFu Semrush

If you tell me roughly how many competitors you monitor and whether Google Shopping/PLAs matter, I can narrow this to 2–3 tools and compare their current pricing and retailer-specific capabilities.

For a mid-market retailer focused specifically on paid-search competitive intelligence, I’d shortlist SpyFu and Semrush.

• SpyFu — particularly strong if your priorities are estimated competitor ad spend + keyword-level intelligence + long-term ad-copy history. It reports estimated monthly budgets, paid keywords, clicks/cost estimates, and historical ad copy. Its current data also emphasizes long historical coverage. SpyFu SpyFu

spyfu.com

• Semrush Advertising Research — a strong alternative if you want those PPC capabilities alongside a broader SEO/competitive-intelligence stack. It provides estimated paid traffic cost/spend, competitor keywords, live ads, keyword changes, and an Ads History view. Semrush Semrush Semrush

semrush.com

• Similarweb — worth considering if the main question is “how large is this competitor's paid-search investment?” rather than detailed ad-copy monitoring. Its PPC Spend metric estimates spend from paid-search visits, paid keywords, and CPC, but it explicitly cautions that the figure is an estimate and can miss keywords/campaigns. Similarweb

What I'd use for your use case

If you need a recurring “competitor watch” covering things like:

Competitor X added 400 keywords → estimated spend increased → new “20% off” messaging appeared → old promotion disappeared

SpyFu is probably the closest fit. Its competitor and Ad History features are explicitly designed around keyword, budget, and ad-copy changes. SpyFu Help Center SpyFu

One important caveat: none of these tools knows a competitor's actual Google Ads spend. The spend figures are modeled estimates based on observed keywords, traffic, CPCs, and other signals, so I'd use them directionally for competitive benchmarking rather than treating them as financial data. Semrush and Similarweb explicitly describe their figures as estimates. Semrush Similarweb

If you tell me your approximate monthly paid-search budget and whether you're primarily Google Search, Shopping, or both, I can narrow this to the most appropriate tool and workflow.

For a mid-market retailer focused on Google paid search, I’d shortlist Semrush and SpyFu.

My pick: Semrush

Semrush lets you enter a competitor domain and see:

• Paid keywords and estimated CPC/traffic.
• Estimated Traffic Cost, which Semrush uses as a proxy for competitor paid-search investment. Semrush Semrush
• Ad copy, including headlines, descriptions, CTAs, associated keywords, and landing pages. Semrush
• Position Changes, so you can identify keywords competitors have started or stopped bidding on.
• Ads History, allowing you to examine how their paid-search presence has changed over time. Semrush

For retail, that combination is useful because you can build something like “competitor entered category X → added these keywords → changed messaging → apparent spend increased.”

SpyFu is particularly interesting for copy monitoring

SpyFu's Ad History is unusually focused on historical PPC creative. It lets you see past competitor ads, the keywords associated with them, and how their messaging evolved. SpyFu SpyFu Help Center

It also estimates monthly ad budget based on observed ad positions and CPC estimates, so you can trend a competitor's apparent investment rather than treating the spend figure as an exact number. SpyFu Help Center

One important caveat: neither tool knows a competitor's actual Google Ads invoice. These are modeled estimates based on observed SERPs, keywords, CPCs, positions, and traffic assumptions. SpyFu explicitly describes its budget as an estimate, and Semrush similarly describes Traffic Cost as estimated spend. SpyFu Help Center Semrush

Bottom line: If you want one platform for a mid-market retail PPC team, I'd start with Semrush. If your primary use case is “tell me exactly how competitors' Google ad messaging has changed over months/years,” I'd give SpyFu a serious look.

For a mid-market retailer managing paid search, I’d look at tools that combine PPC keyword discovery + estimated spend/traffic + ad copy history. No tool can see a competitor’s actual Google Ads spend (Google does not expose that), so the spend numbers are directional estimates based on observed ads, rankings, CPCs, search volume, and impression signals. meertrack

My shortlist:

For your specific requirements:

1. “Estimate competitor keyword spend”

Best fits:

• Semrush — good for seeing paid keyword footprints, CPC estimates, traffic estimates, and competitor trends. Semrush
• SpyFu — useful for quick competitor budget estimates and historical views. SpyFu

Use the spend estimates as relative signals:

• “Competitor A is likely investing heavily in branded shopping terms”
• “Competitor B entered our category keywords recently”
• “Competitor C appears to have reduced paid coverage”

Avoid treating “$250K/month estimated spend” as an actual budget.

2. “Track ad copy changes”

Best fits:

• Semrush — has historical ad examples and ad copy views. Semrush
• SpyFu — strong for seeing how competitors have tested messaging over time. SpyFu
• Dedicated monitoring tools can be useful if you want alerts when competitors change messaging. Outmano

For a retailer, I’d specifically monitor:

• Promo language (“20% off,” “free shipping,” “members save”)
• Price claims
• Shipping/returns promises
• Category pushes (“new arrivals,” “holiday,” “back to school”)
• Brand conquesting

My recommendation for a mid-market retailer

If you already have a typical marketing stack:

Primary tool: Semrush
Secondary/cheaper PPC specialist: SpyFu
Add-on if competitors are very aggressive: a dedicated ad-monitoring tool for alerts

A practical workflow:

1. Track 5–10 direct competitors.
2. Export their paid keyword sets monthly.
3. Tag keywords by category (brand, category, SKU/product, seasonal).
4. Save ad copy snapshots.
5. Compare changes against your own auction insights and impression share.

One caveat for retail: make sure the tool handles Shopping Ads/product feeds well. Text-search PPC intelligence alone can miss a large portion of competitive pressure in categories like apparel, electronics, beauty, and home goods.

For a mid-market retailer managing paid search, the strongest competitive intelligence tools for estimating competitor keyword spend + ad copy changes are:

Semrush SpyFu SimilarWeb## Recommendation for a mid-market retailer

I’d usually shortlist:

1. Semrush — best primary tool

Use it if you need:

• Competitor paid keyword overlap
• Estimated spend trends
• Ad copy comparisons
• Landing page analysis
• Ongoing reporting to merchandising/marketing leadership

Semrush’s Advertising Research suite specifically provides competitor paid keywords, estimated ad spend/traffic cost, ad examples, and ad strategy trends. Semrush Semrush

2. SpyFu — best companion tool for PPC managers

Use it if your day-to-day work is:

• “What keywords did this competitor start buying?”
• “What ads have they been running for months?”
• “What messaging appears to be their evergreen winner?”

SpyFu is particularly strong for historical Google Ads keyword and ad variation research. SpyFu SpyFu

3. Similarweb — if you report upward

Useful when leadership asks:

• “Are competitors increasing digital investment?”
• “Who is gaining share of voice?”
• “Are they shifting budget between search, display, social, video?”

It is broader than PPC keyword intelligence and better suited for market-level views. SimilarWeb

Important caveat

No third-party tool can see a competitor’s exact Google Ads spend. These platforms estimate spend using observed keywords, rankings, click models, CPC data, and traffic estimates. Treat spend numbers as directional (e.g., “Competitor A is likely spending 2–3× more than Competitor B”), not as finance-grade figures. Semrush

For a retailer, I’d typically build a stack like:

• Semrush → monthly competitor dashboard
• SpyFu → deep dives on top 10 competitors
• Google Ads Auction Insights → your actual overlap/impression share
• Google Ads Transparency Center → verify current creative where possible

A practical workflow is to track 10–20 competitors weekly for:

• new keyword categories entered
• branded keyword bidding
• spend spikes
• new promotions in copy
• changes in value propositions (“free shipping,” “20% off,” “price match,” etc.)

That usually produces more actionable insight than trying to find a perfectly accurate competitor budget number.

For a mid-market retailer focused specifically on paid-search competitive intelligence, I’d shortlist SpyFu and Semrush, with Similarweb as a useful third option.

My pick: SpyFu

SpyFu is probably the closest match to your requirements because it combines:

• Estimated competitor ad budgets and PPC clicks. SpyFu SpyFu
• Competitor keyword coverage, including keywords they've historically bought.
• Historical ad copy showing how competitors' messaging has changed over time. SpyFu says its Ad History reaches back more than 18 years. SpyFu
• Ability to see ad copy changes and keyword changes together, which is particularly useful for detecting campaign strategy shifts. SpyFu Help Center
• A relatively strong value proposition if you need to monitor several retailers rather than buy an enterprise intelligence platform.

spyfu.com

Semrush: best alternative

Semrush is arguably the better choice if your team already uses it for SEO, keyword research, and broader competitive analysis.

Its Advertising Research product provides:

• Estimated traffic cost/spend at the competitor and keyword level. Semrush Semrush
• Competitor paid keywords and position changes.
• Ad copy and historical ad activity, including the keywords associated with specific ads. Semrush Semrush
• Reports for identifying new, lost, improved, and declining competitor keywords, which is handy for ongoing monitoring. Semrush

semrush.com

Similarweb: better for the budget/market picture

Similarweb is worth considering if your real question is "How aggressively is this competitor investing in paid search?"

Its PPC Spend metric estimates monthly competitor spend using paid-search traffic, paid keywords, and CPC data, and lets you examine changes over time. Similarweb

The tradeoff is that I'd favor SpyFu/Semrush for hands-on keyword and ad-copy intelligence.

support.similarweb.com

Bottom line

One important caveat: none of these gives you a competitor's actual Google Ads spend. These are modeled estimates based on observed ads, keywords, traffic, CPCs, and related signals. Semrush explicitly describes its figures as estimates, and Similarweb details several sources of potential variance. Semrush Similarweb

If I were equipping a mid-market retail PPC team with one subscription, I'd start with SpyFu; if you already have Semrush in the stack, I'd use its Advertising Research rather than buying another platform.

For your use case, I’d shortlist Semrush and SpyFu, with SpyFu probably the better fit if competitor PPC intelligence is the primary job.

• spyfu.com — best for competitor PPC depth. It estimates competitors’ monthly Google Ads budget, paid keywords and clicks, and tracks those metrics over time. Its Ad History also shows historical ad variations and when copy changed. SpyFu SpyFu Help Center
• semrush.com — best all-around marketing suite. Advertising Research estimates paid traffic/spend, shows competitors' keywords, live ads, ad history, position changes, and landing pages. Semrush Semrush
• If your key question is “what changed in their messaging?”, SpyFu has a particularly useful historical view: it flags new ad variations month-to-month and lets you see which copy competitors repeatedly retained. SpyFu Help Center

My recommendation

For a mid-market retailer managing paid search, I'd start with SpyFu if you're primarily trying to answer:

“How much are competitors likely spending, which keywords are driving that spend, and what ads are they testing?”

I'd choose Semrush if you also want the same platform for SEO, keyword research, competitive analysis, and broader marketing intelligence.

One caveat: neither can know a competitor's actual Google Ads spend. Their spend figures are modeled estimates based on observed keywords, rankings/positions, CPCs, traffic, etc. SpyFu explicitly describes its budget as an estimate based on average ad position and CPC estimates. SpyFu Help Center

If you tell me your rough annual paid-search budget and whether you're mostly Google Shopping, Search, or both, I can also give you a 3–5 tool comparison (SpyFu vs. Semrush vs. Similarweb vs. Ahrefs, etc.) specifically for retail competitive intelligence.

For a mid-market retailer focused specifically on paid search competitive intelligence, I’d shortlist these:

• semrush.com — best overall fit. Its Advertising Research combines competitor paid keywords, estimated spend/traffic cost, ad copy, position changes, and historical ad data. The Positions report can estimate monthly cost at the keyword level, while Ads History shows how ads changed over time. Semrush Semrush Semrush
• spyfu.com — best if ad-history depth is the priority. It provides estimated monthly PPC budgets, paid keywords/clicks, historical ad copy, and keyword-level ad history. SpyFu says its historical ad library goes back many years and can show which copy competitors repeatedly used. SpyFu SpyFu SpyFu Help Center
• Similarweb — worth considering if you want paid search intelligence alongside broader traffic/channel benchmarking, but I'd favor Semrush or SpyFu for your two specific requirements.

My pick

Semrush would be my first demo for a retailer. It gives you a useful workflow:

Competitor → paid keywords → estimated cost → position changes → ad-copy history → landing pages.

That makes it easier to answer questions like “Did Target competitor X suddenly increase investment in ‘running shoes’?” and “What offer/messaging did they introduce when they did it?” Semrush Semrush

One important caveat: competitor spend figures are estimates, not their actual Google Ads invoices. Semrush explicitly describes its Traffic Cost/Costs figures as estimates based on observed paid-search activity. Semrush

If you tell me your approximate monthly paid-search spend and number of competitors, I can also give you a Semrush vs. SpyFu recommendation by price/value and the exact reports I'd use for retail PPC.

For a mid-market retailer, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice if your main questions are “How much are competitors likely spending, on which keywords, and how is their messaging changing?”

• semrush.com — best overall. It estimates competitor paid-search spend at the keyword level via “Traffic Cost,” shows paid keywords/CPCs, and provides Ad Copies plus Ads History for tracking creative and messaging over time. Its historical advertising data goes back to 2012, although the current Ads History report is focused on a 12-month timeline. Semrush Semrush Semrush
• spyfu.com — best value / PPC-focused alternative. SpyFu is particularly strong for competitor PPC history: estimated ad spend, paid keywords, clicks, budget trends, and historical ad copy. It explicitly lets you track ad budget changes and ad-copy/keyword changes, which fits your use case very closely. SpyFu SpyFu Help Center

My pick

If you're buying one: I'd choose Semrush for a retailer because you get the PPC intelligence plus broader competitive/SEO research in the same platform.

One important caveat: neither tool knows a competitor's actual Google Ads spend. Their spend figures are modeled estimates based on observed ads, keywords, CPCs, traffic and related signals. Treat them as directional—particularly at the individual-keyword level—not as accounting-quality numbers. Semrush describes its figure as estimated monthly cost, while SpyFu similarly provides estimated ad spend/budget data. Semrush SpyFu Help Center

If your primary goal is weekly competitive monitoring—e.g., “Competitor X increased paid coverage on these 30 keywords and changed its promotion from 20% off to free shipping”—I'd lean SpyFu for the PPC workflow, whereas Semrush is better if you want that embedded in a larger market-intelligence stack.

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice for a mid-market retailer.

• semrush.com — best overall. It estimates competitor paid-search spend at both the domain and keyword level, shows paid keywords, CPC, traffic, and estimated costs, and has historical ad/keyword data. Its Ad Copies and Ads History reports let you see competitor headlines, CTAs, landing pages, and how messaging changes over time. Semrush Semrush Semrush
• spyfu.com — best if historical PPC intelligence is the priority. It estimates monthly Google Ads budgets, paid clicks and keyword activity, while its Ad History goes deep into historical ad variations and lets you identify copy competitors repeatedly used. SpyFu SpyFu SpyFu Help Center

My pick

Semrush if you want one platform for competitive search intelligence across a retailer's market. Its Traffic Cost and keyword-level Costs are particularly useful for building a rough competitor-spend model. Semrush

SpyFu is compelling if your main workflow is: “What keywords are they buying, roughly how much are they spending, and exactly how has their ad copy evolved?” SpyFu SpyFu Help Center

One caveat: neither gives you competitors' actual Google Ads spend. These are modeled estimates based on observed keywords, rankings/positions, CPCs, traffic and other signals, so I'd use them directionally rather than treating the dollar figures as audited budgets. Semrush SpyFu Help Center

If you tell me your approximate monthly paid-search budget and number of markets/competitors, I can also recommend Semrush vs. SpyFu vs. Ahrefs specifically for a mid-market retail workflow.

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu as the slightly better fit if your priority is competitor PPC intelligence.

My pick: SpyFu

SpyFu specifically exposes competitors' paid keywords, estimated monthly budgets, clicks and costs, and lets you track PPC budgets over time. SpyFu SpyFu

Its Ad History is particularly useful for what you're asking: you can see historical competitor ad variations and identify messaging they've repeatedly used, rather than just seeing the current creative. SpyFu says its historical PPC data goes back many years. SpyFu

When I'd choose Semrush instead

If your team already uses Semrush for SEO, I'd probably stay within Semrush rather than buy another platform. Its Advertising Research gives you:

• competitor paid keywords and estimated spend/traffic cost
• keyword-level estimated costs
• position and keyword changes over time
• competitor ad copy, headlines and CTAs
• historical ad activity
• landing pages associated with ads Semrush Semrush Semrush

One important caveat: neither tool knows a competitor's actual Google Ads spend. The spend figures are modeled estimates based on observed keywords, traffic, CPCs, positions, etc. Semrush explicitly describes Traffic Cost as an estimate, for example. Semrush

Bottom line: If the buying decision is primarily “Which tool gives my paid-search team the best view of competitors' keywords, estimated spend, and evolving ad copy?” → SpyFu. If you want that capability integrated with a larger SEO/competitive-intelligence stack → Semrush.

For your specific use case, I’d shortlist SpyFu and Semrush, with SpyFu as my first pick if competitor keyword spend and ad-copy evolution are the priorities.

My recommendation: SpyFu

spyfu.com is particularly aligned with what you're asking for. Its PPC research estimates competitor monthly ad budgets, paid clicks, paid keywords and spend, while its Ad History shows how competitors' ads have evolved over time. SpyFu SpyFu Help Center

The useful part for a retailer is that you can look at a competitor and answer questions like:

• Which non-brand/category keywords are they investing in?
• What does their estimated spend look like by keyword?
• Which keywords have they added or dropped?
• Which headlines/CTAs have persisted versus disappeared?
• How has their ad messaging changed over months or years?
• Which keyword + copy combinations appear repeatedly?

SpyFu specifically says its Ad History can show historical ad variations and the keywords associated with them, making it particularly useful for tracking messaging changes. SpyFu SpyFu Help Center

When I'd choose Semrush instead

semrush.com is probably the better choice if you want competitive paid search intelligence integrated with a broader SEO/content/market-intelligence stack.

Its Advertising Research includes competitor paid keywords, estimated traffic cost, position changes, live ads and historical ad trends. Semrush Semrush Its Ad Copies report also connects particular ads to the keywords triggering them and provides historical context. Semrush

One important caveat: neither platform knows a competitor's actual Google Ads spend. Their "spend" or "traffic cost" figures are modeled estimates based on observed keywords, CPCs, positions/traffic and related signals. SpyFu explicitly describes its monthly ad budget as an estimate. SpyFu Help Center

Bottom line: If I were running paid search for a mid-market retailer and could buy only one for this particular job, I'd start with SpyFu. If you also need SEO, competitive content research, market analysis and broader marketing intelligence, I'd lean Semrush.

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu as my first pick if your priority is specifically competitor spend + ad-copy change tracking.

Best fit: spyfu.com

SpyFu is particularly strong for PPC competitive intelligence:

• Estimated competitor ad spend/budget and paid clicks.
• Paid keywords and estimated costs at the keyword level.
• Historical ad copy going back many years, so you can see which headlines/messages competitors introduced, retained, or dropped.
• Ad History lets you track how copy evolved over time and connect ads to the keywords triggering them. SpyFu SpyFu SpyFu
• It also has competitor tracking that lets you compare keyword growth, clicks, and ad-budget changes. SpyFu Help Center

Strong alternative: semrush.com

Semrush's Advertising Research is arguably better if you want broader SEO + PPC intelligence in one platform. It provides:

• Competitor paid keywords and estimated paid traffic.
• Traffic Cost, an estimate of what the competitor is spending to generate that traffic.
• Keyword-level cost estimates.
• Current competitor ad copy and the keywords associated with it.
• Historical paid-search trends and position changes. Semrush Semrush Semrush

My recommendation

One caveat: neither tool knows a competitor's actual Google Ads spend. Their spend figures are modeled estimates based on observed ads, rankings, traffic, CPCs, etc. So I'd use them for relative benchmarking and trend detection, not as literal budget numbers. Semrush explicitly describes its figure as estimated spend/traffic cost. Semrush Semrush

If you're deciding between the two for a $50M–$500M retailer, I can also give you a feature-by-feature comparison specifically for retail PPC (Shopping, PMax, brand/non-brand, competitor monitoring, alerts, and reporting).

For a mid-market retailer, I’d shortlist Semrush and SpyFu, with Semrush as the better all-around choice if your primary questions are “what are competitors spending?” and “where are they changing strategy?”

My pick: Semrush

semrush.com

Semrush explicitly provides estimated competitor ad spend/“Traffic Cost,” including keyword-level cost estimates, plus the keywords competitors bid on and their live ad copy. Its Position Changes report lets you identify new/lost keywords and changes in paid-search visibility, with historical data going back to 2012. Semrush Semrush Semrush

For a retailer, that makes it useful for questions like:

• “Which competitors are increasing paid-search investment?”
• “Which product/category terms are consuming their estimated budget?”
• “Did they suddenly start bidding on our category terms?”
• “What messaging/CTAs are they using?”
• “Which ad copy has persisted versus recently changed?”

When I'd choose SpyFu instead

spyfu.com

SpyFu is particularly compelling if ad-copy history is the priority. Its Ad History lets you see historical competitor ads, the keywords associated with them, landing pages, and how messaging evolved over time. It also provides estimated budget trends. SpyFu SpyFu Help Center

So if your workflow is essentially “show me what Target/Wayfair/etc. have been testing in Google Ads over the past year, and estimate how aggressively they're investing,” I'd lean SpyFu.

One caveat: neither tool knows a competitor's actual Google Ads spend. The spend figures are modeled estimates based on observed ads, keywords, rankings, CPCs, traffic, etc., so I'd use them for directional benchmarking and trend detection, not as finance-grade numbers. Semrush itself describes Traffic Cost as an estimate based on CPC rates. Semrush

Bottom line: Semrush for a broader competitive-intelligence program; SpyFu if PPC/ad-history analysis is the core job. For a mid-market retailer, I'd probably start with Semrush, then use SpyFu if the team needs deeper historical ad-copy forensics.

For a mid-market retailer, I’d shortlist spyfu.com and semrush.com, with SpyFu as the better fit if your two requirements are specifically competitor spend + ad-copy history.

My pick: SpyFu

• Estimated competitor spend: SpyFu estimates monthly ad budget using observed ad position and CPC data, and lets you track budget changes over time. SpyFu Help Center SpyFu
• Keyword intelligence: It shows paid keywords, estimated clicks, and spending, including competitor keyword overlap. SpyFu SpyFu Help Center
• Ad-copy changes: Its Ad History is particularly strong—it maintains historical competitor ads and lets you see different variations over time, including which copy has persisted. SpyFu
• Retail use case: You can reverse-search ads to see the keywords associated with them, which is useful for connecting messaging changes to product/category terms. SpyFu

Semrush is the stronger all-around alternative

Semrush's Advertising Research gives you paid keywords, estimated traffic, CPC, estimated costs, position changes, competitors, and ad copies in one workflow. Its Ad Copies report also connects specific ads to the keywords triggering them. Semrush Semrush Semrush

For a retailer, Semrush has an additional advantage if you care about Google Shopping/PLAs: its PLA Research covers competitor product-ad keywords, products, landing pages, titles, pricing, and creatives. Semrush

Bottom line: If you're primarily building a paid-search competitive-intelligence dashboard, I'd start with SpyFu. If the retailer also needs SEO, Shopping/PLA, landing-page, and broader market intelligence, I'd lean Semrush.

One caveat: treat both vendors' "spend" figures as estimates, not actual competitor budgets. They're modeled from observed SERPs, CPCs, traffic, and ad positions rather than competitors' Google Ads accounts. SpyFu Help Center Semrush

For a mid-market retailer, Semrush Advertising Research would be my first choice if your two requirements are specifically estimated competitor keyword spend + tracking ad-copy changes.

Why I'd lean Semrush

Semrush gives you estimated spend ("Traffic Cost") by competitor and keyword, plus paid-keyword positions, CPC and traffic estimates. www.semrush.com

For creative monitoring, its Ads History shows when a competitor's ad appeared for a keyword, its position, and the actual ad copy/landing page over time. The current historical view goes back 12 months in this report. www.semrush.com

That combination is particularly useful for retail because you can build something like:

Competitor → category → keyword → estimated spend → ad message → landing page → change over time

When I'd choose SpyFu instead

If your primary question is "What has this competitor been testing in Google Ads, and what messaging have they kept?", I'd seriously consider SpyFu. It emphasizes historical PPC/ad data and reports estimated monthly budgets, clicks, and keyword costs. www.spyfu.comwww.semrush.com

Its Ad History is particularly deep, with historical ad copy and the keywords associated with those ads. www.semrush.comwww.spyfu.comwww.spyfu.comwww.semrush.com

My recommendation: start with Semrush if you need one platform for paid-search competitive intelligence. Choose SpyFu if ad-copy/creative history is more important than the broader competitive-search toolkit.

One caveat: neither tool can know a competitor's actual Google Ads spend. These are modeled estimates based on observed ads, rankings, CPCs, traffic and related signals, so I'd use them for directional benchmarking and trend detection, not as audited budget figures. www.spyfu.comwww.semrush.com

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu as the better fit if your priority is specifically competitor PPC intelligence.

My pick: SpyFu

spyfu.com is particularly strong for the two things you mentioned:

• Estimated competitor spend: shows estimated monthly Google Ads budget, paid keywords, clicks, CPCs, and spend trends. SpyFu Help Center SpyFu Help Center
• Keyword-level intelligence: lets you see which keywords competitors have bought, including historical terms and recurring keywords. SpyFu
• Ad-copy history: its Ad History tracks competitor ads over many years, letting you see how headlines/messaging changed and which variants persisted. SpyFu
• Competitive monitoring: you can track changes in competitor spend, ads, keywords, and emerging advertisers. SpyFu

Semrush is the stronger all-around alternative

semrush.com gives you similar PPC intelligence: paid keywords, estimated traffic/spend, competitor positioning, live ads, and historical ad trends. Its Traffic Cost metric estimates what the observed paid traffic would cost, including at the keyword level. Semrush Semrush

Its Ads Copies report is particularly useful for systematically analyzing competitors' headlines, CTAs, landing pages, and the keywords associated with each ad. Semrush

One caveat: neither tool knows a competitor's actual Google Ads budget. These are modeled estimates based on observed ads, rankings/positions, CPCs, traffic and related signals. SpyFu explicitly describes its budget as an estimate of Google Search ad spending. SpyFu Help Center

If you're building a competitive-search dashboard for a retailer, I'd lean SpyFu for PPC intelligence, then use Semrush if you also want SEO, Shopping, and broader market intelligence in the same platform.

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu as my first pick if competitor ad-copy history is especially important.

My pick: SpyFu

spyfu.com

SpyFu specifically exposes estimated competitor ad spend, paid keywords, clicks, CPCs, budget trends, and ad history. Its Ad History lets you see how competitor copy evolved and which ads continued running over time. SpyFu SpyFu

For your use case, that's useful because you can build a recurring watchlist around, say, 10–20 retail competitors and monitor:

• Estimated monthly PPC budget/spend
• Keywords they're entering or dropping
• Changes in keyword coverage
• CPC/traffic estimates
• New versus persistent ad variants
• Headlines/messaging that persist over time
• Landing pages associated with ads
• Seasonal changes in their paid-search strategy

SpyFu also explicitly supports tracking ad-budget changes alongside keyword and ad-copy changes, which is particularly relevant to competitive monitoring. SpyFu Help Center

When I'd choose Semrush instead

semrush.com

Semrush is arguably the better choice if you want the PPC intelligence integrated into a larger SEO/competitive-intelligence stack. Its Advertising Research reports provide competitor keywords, estimated traffic cost/spend, position changes, historical ads, and ad copy. Semrush Semrush

One particularly useful feature is keyword-level estimated cost: Semrush's Costs column estimates monthly spend for individual paid-search terms, while Traffic Cost gives you an aggregate view. Semrush

One important caveat

Neither should be treated as the competitor's actual Google Ads billing data. These are modeled estimates based on observed SERPs, keywords, CPCs, traffic, and ad activity. I'd use the numbers primarily for directional benchmarking—e.g., "Competitor A appears to have increased paid-search investment ~30% and added 800 keywords"—rather than claiming they spent exactly $X.

Bottom line: If your primary question is "What are competitors spending, what keywords are driving that spend, and how is their ad messaging changing?", I'd trial SpyFu first, then compare it against Semrush on 5–10 of your most important competitors. SpyFu's historical ad functionality is particularly strong for the copy-change part of your question. SpyFu SpyFu Help Center

For a mid-market retailer, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice if your priority is both estimated spend and monitoring changes in competitor messaging.

• semrush.com — best overall. It estimates competitor paid-search traffic cost/spend at the keyword level, shows paid keywords and positions, and lets you examine competitor ad copy and landing pages. Its historical advertising data goes back to 2012. Semrush Semrush
• spyfu.com — best for deep PPC history. It estimates monthly budgets, paid clicks and keyword-level activity, while its Ad History tracks historical ad variations and can show when copy changed. SpyFu SpyFu Help Center
• Similarweb is worth considering if you also want broader competitive traffic/channel intelligence, but for the specific combination of paid-search spend estimates + ad-copy history, I'd put Semrush/SpyFu ahead.

What I'd choose

One important caveat: neither tool knows a competitor's actual Google Ads spend. The spend figures are modeled estimates based on observed keywords, rankings/visibility, CPCs and traffic. Semrush explicitly describes its "Traffic Cost" as an estimated cost/value of the paid traffic, while SpyFu estimates budget using average ad position and CPC estimates. Semrush SpyFu Help Center

For your use case, I'd start with Semrush, then consider SpyFu if competitive ad-history analysis is a major part of your workflow. Semrush's Ads Copies report is particularly useful for seeing headlines, CTAs, associated keywords and landing pages, while its historical reports let you examine how competitors' paid-search strategies evolve. Semrush

If you tell me roughly how many competitors you monitor and your monthly tool budget, I can also compare Semrush vs SpyFu vs Similarweb specifically for a mid-market retail paid-search team.

For your use case, I’d shortlist SpyFu and Semrush, with SpyFu as my first choice if paid-search competitive intelligence is the primary job.

My pick: SpyFu

spyfu.com is particularly aligned with what you're asking for. It estimates competitors' paid keywords and ad spend, lets you track PPC budget/click/ad-count changes over time, and has an Ad History capability for seeing how competitors' copy evolves. SpyFu SpyFu Help Center

Its Ad History is especially useful for a retailer: you can look at which messages persist, which ads disappear, and which keywords are associated with particular creative. SpyFu currently advertises a very deep historical PPC archive. SpyFu SpyFu Help Center

When I'd choose Semrush instead

semrush.com is probably the better choice if you also want SEO, Shopping/PLA research, keyword gaps, and broader competitive intelligence in the same platform. Its Advertising Research reports provide estimated spend/traffic cost, paid keywords, competitor overlap, live ad copy, and historical position/ad changes. Semrush Semrush Semrush

One useful distinction: neither tool knows a competitor's actual Google Ads spend. The spend numbers are modeled estimates based on observed keywords, traffic, CPCs, etc. Semrush explicitly describes its "Traffic Cost" as an estimated cost, for example. Semrush

Bottom line: for a mid-market retailer where the question is "What are competitors bidding on, roughly what are they spending, and how are their ads changing?" → start with SpyFu. If your team already uses Semrush for SEO and wants one consolidated platform → Semrush is likely the better organizational choice.

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu probably the better fit if competitor spend estimation + ad-copy history are your two primary requirements.

My pick: SpyFu

SpyFu explicitly estimates monthly ad budget, paid clicks, and paid keywords. Its budget estimate is derived from estimated ad position and CPC for the keywords it observes. SpyFu Help Center

More importantly for your use case, its Ad History lets you see historical competitor creative and identify when ad variations appeared or disappeared. SpyFu says its current archive covers ads going back many years and lets you reverse-search ads against the keywords they ran on. SpyFu SpyFu Help Center

spyfu.com

When I'd choose Semrush instead

Semrush is particularly attractive if your paid-search team already uses it for SEO. Its Advertising Research reports provide:

• paid keywords and estimated paid traffic
• Traffic Cost, an estimate of the cost to generate that paid traffic
• competitor overlap
• live ad copy
• Position Changes showing keywords competitors gained/lost
• Ads History, including monthly ad appearances and the creative shown. Semrush Semrush

The big advantage is that you can connect PPC intelligence with your broader SEO/competitive workflow rather than maintaining a separate tool.

semrush.com

One caveat: neither tool knows a competitor's actual Google Ads spend. Treat the spend figures as modeled estimates, useful for relative competitive intensity and trend detection, not as finance-grade estimates.

If I were setting this up for a retailer, I'd use SpyFu for competitor PPC monitoring and build a monthly dashboard tracking estimated spend → paid keyword count → new/lost keywords → new ad variants → offer/message changes. That gives you much more actionable intelligence than simply watching competitor ads.

For a mid-market retailer managing paid search, I’d shortlist tools that can do two things well:

1. Estimate competitor keyword footprint / spend signals (directional, not exact)
2. Track competitor ad copy and messaging changes over time

No third-party tool can see a competitor’s actual Google Ads budget or bids, so spend estimates are modeled from observed ads, keyword coverage, CPC estimates, and visibility signals. Treat them as relative intelligence (“Competitor A is ramping spend on these categories”) rather than accounting-grade numbers. meertrack Semrush

Best options

My recommendation for a mid-market retailer

If you mainly care about Google Search competitors:

Start with Semrush + SpyFu.

• Semrush: use for ongoing reporting:

• competitor paid keywords
• estimated paid traffic cost
• ad copy examples
• keyword overlap
• new/lost paid terms

Semrush’s Advertising Research product specifically supports competitor keyword discovery, ad copy analysis, and historical paid-search trends. Semrush

• SpyFu: use for deeper one-off investigations:

• “What keywords has this retailer bought for years?”
• “What promotions/messages have they tested?”
• “Where are they suddenly expanding?”

SpyFu positions itself around competitor PPC keywords, ad history, and estimated spend signals. SpyFu

If your biggest pain is “tell me when competitors change strategy”

Look at newer monitoring-focused tools such as Outmano or similar ad-monitoring platforms. They focus more on alerts for:

• new keywords
• paused campaigns
• headline/description changes
• competitor messaging shifts

Outmano## Retail-specific workflow I’d use

1. Pick 10–20 competitors:

• direct retailers
• marketplaces
• aggressive DTC brands
• category specialists
• Track:

• brand terms
• category terms (“women’s running shoes”)
• high-margin products
• seasonal terms (“holiday gifts,” “back to school”)
• Build a weekly competitor report:

• estimated paid keyword growth
• new ad themes
• promotions/offers
• landing page changes
• impression-share pressure from your own auction insights

For a typical mid-market retailer, I’d usually choose Semrush as the core platform, add SpyFu for deeper PPC archaeology, and only add a dedicated ad-monitoring tool if you need automated alerts on creative changes. Semrush SpyFu

For your specific use case, I’d shortlist Semrush and SpyFu, with SpyFu probably the better fit if competitor ad-copy history is a major requirement.

My pick: SpyFu

spyfu.com is unusually focused on exactly what you're asking for. It estimates competitors' paid keywords, clicks and ad spend, and lets you track budget changes over time. SpyFu SpyFu Help Center

Its Ad History is the standout feature: you can see historical ad variants, when they appeared, which keywords they were associated with, and how competitors' messaging evolved. SpyFu says its archive extends back roughly 20 years. SpyFu SpyFu Help Center

When I'd choose Semrush instead

semrush.com is the better choice if your team already uses Semrush or you want PPC intelligence alongside SEO, keyword gap analysis, and broader competitive research.

Its Advertising Research reports provide paid keywords, estimated paid traffic, Traffic Cost/spend estimates, position changes, and competitor ad copy. Semrush Semrush Semrush also explicitly supports keyword-level spend estimates through its Positions report. Semrush

For a mid-market retailer, I'd start with SpyFu if the primary question is “What are my competitors spending and what messages are they changing?” If the requirement is more broadly “build a competitive search-intelligence stack,” I'd lean Semrush.

One caveat: neither tool can know a competitor's actual Google Ads spend. These are modeled estimates based on observed keywords, rankings/positions, traffic and CPC data, so I'd use them for relative trends and competitive intensity, rather than treating the dollar figures as audited budgets.

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the better overall fit for a mid-market retailer.

My pick: Semrush

semrush.com is particularly well suited if you need to answer questions like:

• “How much more aggressively is Competitor A bidding?” Semrush provides estimated monthly spend/“Traffic Cost,” including estimates at individual keyword level. Semrush Semrush
• “What keywords did they start or stop buying?” Its Position Changes report identifies new/lost paid keywords and changes in paid-search positions. Semrush
• “What messaging are they using?” Ad Copies shows their actual headlines, descriptions, display URLs and landing pages. Semrush
• “When did their messaging change?” Ads History provides a month-by-month view of ads and keyword activity; the current report covers 12 months. Semrush

When I'd choose SpyFu instead

spyfu.com is arguably stronger if historical competitive analysis is the main requirement. It tracks competitor PPC budgets, clicks, keyword counts and ads over time, while its Ad History provides a much deeper historical archive of competitor ad variations. SpyFu SpyFu

So, for a retailer, I'd use Semrush for ongoing competitive monitoring and budget/keyword benchmarking, and consider SpyFu if you particularly care about reconstructing competitors' historical promotions, messaging tests, and keyword behavior.

One caveat: neither tool can see a competitor's actual Google Ads budget. Treat “spend” as a modeled estimate, not financial disclosure; actual spend can differ substantially because of bids, impression share, match types, geo/device targeting, and Google auction dynamics.

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the safer default for a mid-market retailer.

My pick: Semrush

Semrush Advertising Research gives you estimated competitor paid-search spend, paid keywords, traffic, CPC/cost data, and competitor overlap. Its Ads History can show a 12-month timeline of when competitor ads appeared, including the ad copy and landing page used. www.semrush.com

That's particularly useful for retail because you can segment competitors by brand vs. non-brand, product/category terms, CPC, landing page, and estimated cost rather than looking only at an aggregate competitor score. www.semrush.com

Where SpyFu may beat it

SpyFu PPC Research is arguably better if your primary question is "What has this competitor been doing in Google Ads over time?" It estimates monthly ad budgets, paid clicks and keywords, and lets you track those metrics historically. www.spyfu.com

Its Ad History is especially useful for creative intelligence: it maintains historical competitor ads and lets you see which messaging/variations persisted and which keywords triggered them. www.spyfu.com

One caveat: neither tool knows a competitor's actual Google Ads spend. These are modeled estimates based on observed ads, rankings, CPCs, traffic, etc. SpyFu explicitly describes its monthly budget as an estimate derived from ad position and CPC estimates. help.spyfu.com

Bottom line:

• Need one platform for PPC + SEO + broader competitive reporting → Semrush.
• Paid-search competitive intelligence is the core job → SpyFu is worth a serious look.
• If you tell me your monthly paid-search budget and roughly how many competitors/SKUs you monitor, I can also compare the current pricing and plan limits of Semrush vs. SpyFu for your specific use case.

For a mid-market retailer, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice for your specific use case.

My pick: Semrush

Semrush's Advertising Research can estimate competitor paid-search spend at the keyword level, show traffic-cost trends, identify keywords competitors have added/lost, and expose their ad copy and landing pages. Its historical position data goes back to 2012, which is useful for analyzing seasonality and longer-term strategy. www.semrush.com

For your workflow, I'd use:

1. Positions → estimate spend and identify high-value competitor keywords.
2. Position Changes → flag new/lost keywords and shifts in bidding emphasis.
3. Ad Copies → monitor headlines, CTAs and messaging.
4. Competitors → find emerging advertisers and compare estimated paid-search investment. www.semrush.com

Semrush Advertising Research

When I'd choose SpyFu instead

If your primary job is PPC competitive intelligence rather than broader SEO/market intelligence, SpyFu is arguably more specialized. It tracks competitor PPC budgets, keywords and ads over time and has particularly deep historical ad-copy data. Its current documentation says its ad-history database reaches back 20 years. www.spyfu.com

The useful distinction is that SpyFu explicitly lets you see how competitors' ad variations evolve month-to-month, making it good for answering questions like “When did this retailer change its promotional messaging?” or “Which version of this ad did they keep running?” help.spyfu.com

SpyFu PPC Research

Bottom line: If you're buying one tool, I'd start with Semrush. If you already have SEO/market intelligence covered and want a dedicated PPC spying tool, I'd seriously consider SpyFu.

One caveat: neither tool has access to competitors' actual Google Ads invoices, so “spend” is an estimate, not their true budget. Semrush, for example, calculates keyword-level cost estimates from observed paid-search activity and CPC/traffic data. www.semrush.comwww.semrush.com

For your use case, I’d shortlist SpyFu and Semrush, with SpyFu as the better fit if competitor ad-copy change history is the priority.

Why I’d lean SpyFu: it specifically tracks competitor PPC budgets over time and lets you inspect historical ad copy, including how messaging evolved and which ads persisted. Its current product pages say you can see competitor keywords, estimated spend, ad tests, and budget changes. www.spyfu.com

SpyFu

Semrush is arguably better if you're already using it for SEO/market intelligence. Its Advertising Research product estimates competitor paid-search spend at both the domain and keyword level, identifies keyword gains/losses, and provides ad-copy reports with headlines, CTAs, triggering keywords, CPC, and historical trends. www.semrush.com

Semrush Advertising Research

My pick for a mid-market retailer

SpyFu if your core question is:

“What are Target/Competitor X/Y spending, what keywords are they entering/exiting, and what messaging are they changing?”

Semrush if the question is broader:

“How does our paid-search competitive landscape compare across keywords, spend, traffic, ads, landing pages, and SEO?”

One caveat: neither gives you competitors' actual Google Ads spend. These are modeled estimates based on observed ads, rankings, CPCs, traffic, etc., so I'd use the numbers directionally rather than treating them as budget truth. Semrush explicitly describes its figures as estimated spend/traffic cost. www.semrush.comwww.semrush.com

If you tell me your approximate monthly paid-search budget and how many competitors you want to monitor, I can also recommend which tier/tool is likely to give you the best ROI.

For your use case, I’d shortlist SpyFu and Semrush, with SpyFu as the first tool I’d trial.

Why SpyFu: it specifically exposes estimated ad spend, paid keywords, clicks and CPC, while its Ad History lets you see historical ad variations and identify when messaging changed. Its current documentation says you can track PPC budget changes over time and click into ad-copy and keyword changes. SpyFu SpyFu Help Center

spyfu.com

Semrush is the closest alternative. Its Advertising Research product provides competitor keywords, estimated ad spend, live ads, and historical ad trends; its Position Changes report is particularly useful for seeing when competitors add/drop paid keywords. Semrush Semrush

semrush.com

One important caveat: competitor “spend” is an estimate, not their actual Google Ads billing data. SpyFu, for example, derives its monthly budget estimate from estimated CPC and average ad position. SpyFu Help Center Semrush likewise describes its keyword-level costs as estimates. Semrush

For a mid-market retailer, I'd lean SpyFu if your primary question is “What are competitors bidding on, how much might they be spending, and what messaging are they testing?” Semrush wins if you want that capability integrated with a broader SEO/content/competitive-intelligence stack.

For your use case, Semrush is probably the best all-around choice, with SpyFu as the strongest alternative.

Why I'd lean Semrush

Semrush's Advertising Research gives you paid keywords, estimated paid traffic, CPCs, traffic cost/estimated spend, competitors, and ad copy in one workflow. Its Position Changes report can also show when competitors add or stop bidding on keywords. www.semrush.comwww.semrush.com

For ad-copy monitoring specifically, its Ad Copies report shows the actual headlines, CTAs and ad text, the keywords triggering each ad, landing pages, and changes in ad position. www.semrush.com

SpyFu is arguably better if historical PPC intelligence is your priority. It reports estimated monthly ad budget and paid keywords, and its Ad History is designed around seeing how competitor ads evolve over time—including which copy they repeatedly reuse. help.spyfu.com

One important caveat: competitor "spend" is an estimate, not their actual Google Ads spend. Both platforms infer it from observed keywords/positions, CPCs, traffic and related signals, so I'd use the numbers directionally for competitive benchmarking rather than treating them as finance-grade estimates. www.semrush.com

My recommendation for a mid-market retailer: start with Semrush if you want one platform for competitor monitoring, keyword gaps, spend benchmarking and creative intelligence. Choose SpyFu instead if your team particularly values long-run PPC/ad-copy history and wants to analyze competitors' testing patterns.

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice for a mid-market retailer.

My pick: Semrush

Semrush Advertising Research is particularly well matched to what you're asking for. It estimates competitor paid-search traffic/spend, identifies paid keywords, shows live ad examples, and provides historical ad data. www.semrush.com

Its Competitors report gives you estimated paid traffic, paid-keyword counts, and "Paid Traffic Price"—essentially an estimated cost to generate the observed traffic. www.semrush.com Its Ad Copies report connects specific ad creative to the keywords triggering it, while showing position changes and CPC/search-volume information. www.semrush.com

That's useful for a retailer because you can build something like:

Competitor → category/brand keywords → estimated spend → new/lost keywords → new ad messaging → landing page

When I'd choose SpyFu instead

SpyFu PPC Research is arguably better if PPC competitive intelligence itself is the primary job. It explicitly tracks estimated competitor spend, clicks, PPC budgets and ad counts over time. www.spyfu.com

Its Ad History is especially compelling: it lets you see historical ad variations and how competitor messaging evolved, including which ads persisted versus disappeared. www.spyfu.com

Bottom line:

• One platform for broader competitive marketing intelligence: Semrush
• Deepest PPC/ad-history workflow: SpyFu
• If you're specifically trying to answer "What are Target/Wayfair/etc. spending, which keywords are they moving into, and what copy did they just change?", I'd trial both against 5–10 of your actual competitors and compare the estimates rather than assuming either spend figure is precise.

One important caveat: neither can see a competitor's actual Google Ads bill. "Spend" is an estimate inferred from observed keywords, positions, traffic, CPCs, and related signals, so use it directionally and focus on changes/trends rather than the absolute dollar figure. www.semrush.com

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the stronger all-around choice for a mid-market retailer.

My pick: Semrush

Semrush's Advertising Research gives you estimated competitor spend (“Traffic Cost”), including keyword-level cost estimates, alongside paid keywords, CPC, traffic, and position changes. www.semrush.com

For ad-copy monitoring, its Ads History provides a 12-month timeline showing when competitors' ads appeared, their positions, and the actual creative associated with each month. That makes it useful for identifying things like new promotions, changed value propositions, seasonal messaging, and discontinued copy. www.semrush.com

Semrush Advertising Research

When I'd choose SpyFu instead

If your primary job is PPC competitive intelligence rather than broader SEO/marketing intelligence, SpyFu is particularly compelling. It tracks competitor PPC budgets, clicks, number of ads, paid keywords, and changes over time, and its Ad History goes much deeper into historical ad variations. www.spyfu.com

SpyFu PPC Research

One caveat: neither tool knows a competitor's actual Google Ads spend. These are modeled estimates based on observed keywords, rankings, CPCs, traffic, and ad activity. Semrush explicitly describes Traffic Cost as an estimated cost to generate the observed paid traffic. www.semrush.com

For a mid-market retailer, I'd lean Semrush if you want one platform for competitive search strategy, while SpyFu gets the nod if deep PPC/ad-history analysis is the primary requirement.

If you tell me your approximate monthly paid-search budget and number of competitor domains, I can also compare the current Semrush vs. SpyFu tiers and tell you which subscription is likely the better ROI.

For your use case, SpyFu is probably the best fit, with Semrush as the stronger all-around alternative.

My pick: SpyFu

SpyFu specifically exposes estimated PPC spend, paid keywords, clicks/CPCs, budget trends, and historical ad activity. It also has an unusually deep Ad History view showing how competitor ads evolve over time. www.spyfu.com

For example, its Ad History can show when a competitor introduces a new ad variation, drops an old one, or keeps a particular message running for an extended period. help.spyfu.com

SpyFu PPC research

Semrush is the better alternative if you want a broader stack

Semrush's Advertising Research estimates competitor paid-search investment and lets you inspect paid keywords, CPC/traffic-cost estimates, position changes, and historical ads. Its Ads Copies report connects specific ad copy to the keywords triggering it. www.semrush.com

Its current documentation specifically describes keyword-level estimated monthly costs and a historical Traffic Cost view, which is useful for monitoring whether a retailer is materially increasing or reducing PPC investment. www.semrush.com

Semrush Advertising Research

For a mid-market retailer, I'd choose SpyFu if the primary question is:

“What are my competitors spending, what keywords are they buying, and what ad messaging are they changing?”

Choose Semrush if you also want competitor SEO, paid search, landing pages, market/competitor discovery, and broader marketing intelligence in the same platform.

One caveat: neither platform has access to competitors' actual Google Ads budgets. The spend figures are modeled estimates, so I'd use them directionally—especially for comparing changes in spend and relative investment, rather than treating a dollar figure as ground truth.

For a mid-market retailer managing paid search, I’d shortlist these tools based on the two capabilities you care about:

1. Estimating competitor keyword spend
2. Tracking competitor ad copy changes over time

www.semrush.comwww.spyfu.com

My recommendation for a mid-market retailer

Primary pick: Semrush Advertising Research

• Use it to benchmark:
  • competitor paid keyword coverage
  • estimated paid traffic
  • estimated traffic cost/spend
  • keyword overlap
  • new entrants into your auction landscape
• It also provides competitor ad examples and historical ad information. www.semrush.com

If your team is mostly Google Ads/PPC operators: SpyFu may actually be the better specialist tool

• It is particularly strong for:
  • seeing competitor keywords they have historically bought
  • estimating spend/click activity
  • reviewing past ad variations and tests www.spyfu.com

A practical stack I’d use

For a retailer spending roughly mid-six to low-seven figures annually on search:

• Semrush → executive reporting, market landscape, competitor benchmarking
• SpyFu → weekly PPC intelligence workflow:
  • “Who started bidding on our category terms?”
  • “Who changed promotions?”
  • “Which competitors are pushing seasonal offers?”

Caveat on spend estimates

None of these tools can see a competitor’s actual Google Ads bill. Their “spend” numbers are modeled estimates based on observed keywords, rankings, CPC assumptions, traffic estimates, and historical ad data. Treat them as directional signals, not accounting data. www.semrush.com

For a retailer, I’d also evaluate whether the tool can segment by brand vs. non-brand keywords, Shopping/PMax visibility, and category-level competitors—those often matter more than total estimated spend.

For your use case, I’d shortlist Semrush and SpyFu, with Semrush as the better all-around choice.

My pick: Semrush

Semrush's Advertising Research specifically combines competitor paid keywords, estimated ad spend, paid traffic, live ad copy, and historical ad activity. Its Ads History report can show keyword-level ad appearances over time, including the ad copy, landing page, CPC and search volume. www.semrush.com

That makes it particularly useful for a retailer where you might want to answer questions like:

• Is Target increasing investment around "women's running shoes"?
• Which competitors are consistently appearing on our highest-value nonbrand terms?
• When did a competitor switch from percentage-off messaging to free-shipping messaging?
• Which keywords have competitors been willing to fund for months rather than testing briefly?

Semrush Advertising Research

SpyFu is arguably better if PPC is the primary job

SpyFu is unusually focused on historical Google Ads intelligence. It provides estimated ad spend, paid keywords, budget/click trends, and historical ad copy, with its current product claiming a 20-year ad-history database. www.spyfu.com

If your main workflow is "show me what competitors have been bidding on and how their ads have evolved", I'd seriously consider SpyFu over Semrush. Its competitor view also lets you track ad-budget changes over time. help.spyfu.com

SpyFu PPC Research

One important caveat: neither tool knows a competitor's actual Google Ads spend. The spend figures are modeled estimates, so I'd use them directionally—especially for comparing trend and relative investment rather than treating "$X/month" as ground truth.

Bottom line:

• One platform for a mid-market retailer → Semrush
• Deepest PPC competitor digging → SpyFu
• Already standardized on Ahrefs → its Paid Search reports are capable, but I'd choose the other two specifically for spend + ad-history intelligence. help.ahrefs.com

For a mid-market retailer focused specifically on paid-search competitive intelligence, I’d shortlist SpyFu and Semrush, with SpyFu as my first choice if your two requirements are estimated competitor spend + ad-copy changes over time.

Why I'd lean SpyFu

SpyFu explicitly provides estimated ad spend, paid keywords, PPC clicks and budget trends, and its Ad History lets you see competitor ad variants and how copy evolved over time. www.spyfu.com

For your use case, that's particularly useful for questions like:

• "Did Target increase spend on this category?"
• "Which competitors started bidding on our brand terms?"
• "When did this competitor introduce a new promotional message?"
• "Which headlines have they kept running for months?"
• "What keywords are associated with each version of their ads?"

SpyFu currently says its ad history goes back 20 years, while its PPC dataset has recently undergone a major expansion. www.spyfu.com

When I'd choose Semrush instead

I'd choose Semrush Advertising Research if your team already uses Semrush or wants PPC intelligence integrated with a larger SEO/competitive-research workflow. It provides estimated traffic cost/spend, paid keywords, position changes, live ads, and historical ad data. www.semrush.comwww.semrush.com

Semrush is particularly nice for a retailer because you can move from competitor → overlapping keywords → estimated traffic/spend → ad copy → landing pages in one workflow. www.semrush.comwww.semrush.com

Bottom line:

• Best dedicated PPC CI: SpyFu
• Best all-around marketing intelligence platform: Semrush
• If ad-copy change detection is the #1 requirement: I'd start with SpyFu.

One caveat: neither tool has access to a competitor's actual Google Ads account, so spend figures are estimates, not audited budgets. Semrush, for example, describes its metric as estimated cost based on paid traffic/CPC. www.semrush.com

For a mid-market retailer managing paid search, the best competitive intelligence tool depends on how deep you need to go. For your specific needs — estimating competitor keyword spend + tracking ad copy changes — I’d shortlist these:

My recommendation for your use case

1. Adthena — if you need the closest thing to a paid search “radar”

• Estimates competitor share of spend, keyword coverage, overlap, and market movement.
• Tracks competitor ad messaging, including changes in headlines, offers, and positioning.
• Strong for retailers where you need to answer questions like:
  • “Who increased spend on our category terms last month?”
  • “Which competitors are appearing more often?”
  • “Did they change their promo messaging?”

www.adthena.com

2. Semrush Advertising Research — probably the best starting point

• Shows competitor paid keywords, estimated traffic cost/spend, ad examples, and historical trends.
• Useful for building recurring competitor reports without an enterprise contract.

www.semrush.com

3. SpyFu — strong if you care about ad history

• Particularly good for seeing:
  • keywords competitors have historically bought
  • ads they have tested over time
  • messaging patterns that persist

www.spyfu.com

A practical stack I’d use for a mid-market retailer

• Semrush → monthly competitor keyword/spend monitoring
• SpyFu → creative history and messaging research
• Google Ads Auction Insights → your actual overlap/impression share data
• Adthena → upgrade when you need category-level intelligence or executive reporting

One caveat: no tool can know a competitor’s exact Google Ads budget. These platforms estimate spend from observed SERPs, keyword coverage, CPC models, impression data, and auction signals. Treat spend numbers as directional — the trend (“they doubled investment in this category”) is usually more reliable than the exact dollar figure. www.adthena.com

For a retailer, I’d prioritize Adthena if you spend heavily in Shopping + Search, and Semrush + SpyFu if you’re in the $50k–$500k/month paid search range and want a good ROI on tooling.

For your use case, I’d shortlist Semrush and SpyFu, with a slight edge to Semrush for a mid-market retailer.

Why I’d pick Semrush: Its Advertising Research reports estimate paid traffic and Traffic Cost, including keyword-level cost estimates, and let you track changes in paid keywords and ad activity over time. Its Ads Copies report shows the actual headlines, CTAs, ad text, triggering keywords and landing pages. www.semrush.com

Semrush Advertising Research

Why SpyFu is a very close second: SpyFu is particularly good at historical competitive PPC. Its Ad History tracks competitor ads over many years, while its competitor tools track estimated budget, clicks, keyword counts and changes over time. www.spyfu.com

SpyFu PPC Research

One important caveat: neither can know a competitor's actual Google Ads spend. The spend figures are modeled estimates based on observed keywords/positions, search volume and CPCs. Treat them as directional—particularly for a retailer with Shopping/PMax, brand terms, geo targeting, or heavy first-party bidding. www.semrush.com

My recommendation for a mid-market retailer

Start with Semrush if you want one platform for:

• competitor estimated spend/budget trends
• keyword overlap and gaps
• ad-copy monitoring
• landing-page intelligence
• broader SEO + paid-search competitive analysis

Choose SpyFu instead if the primary question is “What have competitors been testing, and how has their messaging changed?” Its historical PPC/ad-copy dataset is especially compelling. www.spyfu.com

If you tell me roughly your annual paid-search budget and whether Google Shopping/PMax is a major component, I can narrow this down further and suggest the best tool for your specific retail setup.

For a mid-market retailer focused specifically on competitor paid-search spend + ad-copy changes, I’d shortlist SpyFu and Semrush, with SpyFu as my first choice for PPC competitive intelligence.

My pick: SpyFu

SpyFu is particularly well aligned with your requirements. It estimates competitor PPC budget, clicks, keywords, and spend trends, and its Ad History lets you see competitors' historical ad variations and how their messaging changes over time. help.spyfu.com

Its historical ad database is a major advantage if you're trying to answer questions like:

• "When did Target X start pushing 20%-off messaging?"
• "Which keywords did they add before their holiday push?"
• "Has their estimated PPC budget increased?"
• "Which headlines have they kept running for months?"
• "Are they pulling back from particular categories?"

SpyFu specifically lets you track ad-budget changes and then drill into ad-copy and keyword changes. help.spyfu.com

SpyFu PPC Competitive Research

When I'd choose Semrush instead

If your team already uses Semrush—or wants SEO, PPC, keyword gap, competitor discovery, and paid-search intelligence in one platform—Semrush may be the better enterprise purchase.

Its Advertising Research provides estimated Traffic Cost (a proxy for monthly competitor spend), keyword-level cost estimates, new/lost paid keywords, competitor ad copy, and historical ad trends. www.semrush.com

Semrush Advertising Research

Bottom line:

• PPC/retail competitive intelligence is the primary job → SpyFu.
• You want one broader marketing-intelligence platform → Semrush.
• Don't treat either tool's "spend" number as actual competitor spend; it's an estimate based on observed ads, traffic, CPCs, and keyword data, so I'd use it directionally rather than as a budget-grade number. www.semrush.com

If you tell me roughly how many competitors/brands you need to monitor and whether you're mainly Google Search or Shopping, I can narrow this down to the best tool and plan tier.

For a mid-market retailer, I’d shortlist SpyFu and Semrush, with SpyFu probably the better fit if competitor ad-copy history is the priority.

My pick: SpyFu

SpyFu specifically tracks competitor paid keywords, estimated ad spend, clicks, ad count and budget changes over time. www.spyfu.com

Its strongest differentiator for your use case is Ad History: you can see historical competitor ad variations, which keywords triggered them, and when copy changed. SpyFu says it has historical Google Ads data going back 20 years. www.spyfu.comhelp.spyfu.com

It also gives you a useful signal for distinguishing persistent messaging from experimentation: repeated ads and consistently purchased keywords are surfaced as stronger/“trusted” combinations. www.spyfu.comhelp.spyfu.com

SpyFu

When I'd choose Semrush instead

If you're already using Semrush for SEO, I'd probably stay in Semrush rather than add another platform. Its Advertising Research reports estimate paid traffic and Traffic Cost, show competitor paid keywords, and provide competitor positioning/overlap analysis. www.semrush.com

Its Ads Copies report also lets you connect specific ad copy to the keywords triggering it, including estimated CPC and historical position changes. www.semrush.com

Semrush Advertising Research

Bottom line:

• Need “What are competitors spending, what keywords are they buying, and exactly how has their copy changed?” → SpyFu.
• Need that plus a broader SEO/market-intelligence stack → Semrush.
• Treat all competitor spend figures as estimates, not actual Google Ads budgets. SpyFu itself explains that its spend/budget figures are calculated from observed SERPs and related data rather than access to competitors' accounts. help.spyfu.com

If you're evaluating this specifically for retail/e-commerce, I can also compare SpyFu vs Semrush vs Similarweb vs Ahrefs on the dimensions that matter most for a paid-search team (competitor spend accuracy, Shopping/PMax visibility, keyword gaps, ad-history depth, alerts, and reporting).