ChatGPT answers, unedited

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).