Answers that name a competitor

If your goal is specifically “someone reaches checkout, abandons, and I want one platform to retarget them across multiple ad networks”, I’d shortlist these:

My practical pick: AdRoll

For the exact use case you described, AdRoll is probably the simplest all-in-one option. Its automation builder can coordinate a campaign across Facebook, Instagram, TikTok, Pinterest and the web, while its ecommerce integrations can identify cart abandoners and trigger retargeting. AdRoll AdRoll

It also supports dynamic product ads, so someone who abandoned a checkout can see the specific product they were considering rather than a generic brand ad. AdRoll

adroll.com

When I'd look at Criteo instead

If you're doing substantial ecommerce volume with a large product catalog, Criteo is worth evaluating. Its dynamic retargeting uses commerce/intent signals and supports premium publisher inventory, social channels, video and dynamic formats. Criteo

One important caveat

I wouldn't automatically assume that one platform = maximum performance. Some sophisticated advertisers deliberately use multiple retargeting providers because different platforms have access to different inventory, identity signals and bidding models. RTB House RTB House

A sensible architecture can therefore be:

Checkout abandonment → first-party audience →

• Meta retargeting
• Google retargeting
• programmatic/open-web retargeting
• email/SMS recovery

with strict exclusion rules so someone who purchases immediately leaves the retargeting pool.

If you tell me your monthly website visitors, monthly ad spend, ecommerce platform (Shopify/WooCommerce/custom), and whether you specifically need Meta + Google + display in one dashboard, I can narrow this down to 2–3 platforms and compare pricing, tracking, attribution, audience rules, and setup complexity.

adroll.com

When I'd look at Criteo instead

If you're doing substantial ecommerce volume with a large product catalog, Criteo is worth evaluating. Its dynamic retargeting uses commerce/intent signals and supports premium publisher inventory, social channels, video and dynamic formats. criteo.com

One important caveat

I wouldn't automatically assume that one platform = maximum performance. Some sophisticated advertisers deliberately use multiple retargeting providers because different platforms have access to different inventory, identity signals and bidding models.

A sensible architecture can therefore be:

Checkout abandonment → first-party audience →

AdRoll is probably the closest fit for your use case. It specifically supports cart-abandoner retargeting and can coordinate campaigns across web/display, Facebook, Instagram, TikTok, Pinterest, and other inventory from one platform. AdRoll AdRoll Help Center

• AdRoll: Best if you want simplicity and one dashboard for ecommerce retargeting.
• Criteo: Better suited to larger ecommerce advertisers wanting sophisticated dynamic-product retargeting and cross-channel optimization. Criteo Criteo Help
• Google/Meta separately: More control, but you manage audiences, budgets, frequency, and reporting independently.

For checkout abandoners specifically, I'd start with AdRoll, particularly if you're on Shopify, WooCommerce, BigCommerce, or Wix. AdRoll

If your goal is one audience/retargeting layer that coordinates email with paid media, I’d shortlist these:

• Customer.io — particularly strong if you want behavioral segments to drive both email and advertising. It can sync segments to Google Ads, Meta/Facebook/Instagram, YouTube, and other destinations; its current integration directory also lists Criteo, Pinterest, TikTok, Bing, and X destinations. Customer.io Customer.io
• Klaviyo — a strong fit if your email provider is already Klaviyo, especially for ecommerce. It can sync lists/segments into Meta, Google, TikTok, and Pinterest for custom/retargeting and lookalike audiences. Klaviyo Help Center academy.klaviyo.com

My recommendation

If you already use Customer.io for email, use Customer.io's ad-audience synchronization rather than adding another retargeting platform. You can create lifecycle/behavioral segments once—for example:

• Viewed product but didn't purchase → Meta + Google retargeting
• Abandoned cart → email + paid retargeting
• Purchased recently → suppress from acquisition ads
• High-value customers → retention campaigns + lookalike audiences

Customer.io automatically synchronizes the segments to the ad networks, rather than requiring recurring CSV exports. Customer.io

If you tell me which email provider you use (Klaviyo, HubSpot, Mailchimp, Customer.io, Braze, etc.) and which ad networks (Meta, Google, TikTok, LinkedIn, Criteo, etc.), I can narrow this to the most appropriate architecture and integration.

If your goal is one audience/segmentation layer driving both email and paid retargeting, I’d shortlist these:

1. Klaviyo — strong fit for ecommerce

If your email provider is already Klaviyo, this is probably the most straightforward architecture. Klaviyo can sync lists/segments to Meta Ads and Google Ads, allowing the same behavioral segments used for email to become ad audiences. It also supports integrations with TikTok and Pinterest. Klaviyo Help Center Klaviyo Help Center Klaviyo

A useful campaign could look like:

• Browsed product, no purchase → abandoned-browse email + Meta/Google retargeting
• Started checkout, no purchase → cart email + retargeting ads
• Purchased → suppress from acquisition/retargeting + move into cross-sell email/ad audience
• High-value customers → email nurture + lookalike audience

One caveat: Meta and Google can take time to process audience updates, and matched audience sizes will generally be smaller than your source email segments. Klaviyo Help Center Klaviyo Help Center

2. Customer.io — better if you need broader orchestration

Customer.io is worth considering if you're not tied to a particular email platform or need more sophisticated event-based segmentation. Its Ad Audiences feature synchronizes segments with Google and Meta, and its integration directory also includes destinations such as TikTok, Pinterest, Criteo Audiences, and Bing Ads. Customer.io Customer.io

It also hashes email/mobile identifiers before sending audience data to ad networks. Customer.io

My practical recommendation

I wouldn't add a separate "retargeting platform" unless you have a specific need for cross-network media buying/optimization beyond audience synchronization. In many setups, the email/CDP layer should own segmentation, while Meta/Google/etc. execute the advertising.

If you tell me which email provider you use (Klaviyo, HubSpot, Braze, Salesforce, Mailchimp, etc.) and which ad networks you need, I can narrow this to the most appropriate architecture and integrations.

Yes. There are several tools now built specifically around first-party visitor tracking + retargeting without depending heavily on third-party cookies.

A useful distinction is whether you want to retarget anonymous visitors or only visitors you can identify through email/CRM data.

Options worth looking at

• AdRoll — explicitly supports retargeting from first-party data such as website visitors, CRM lists, and ecommerce signals, rather than requiring third-party cookies. AdRoll
• Klaviyo — particularly good for ecommerce. Its new First-Party ID uses a server-side cookie on your own domain to recognize known returning visitors for longer and feed that into marketing automation. It does not identify brand-new anonymous visitors by itself. Klaviyo Help Center
• Gobot — focuses on identifying anonymous site visitors and turning them into first-party audiences that can be used for email/SMS retargeting. Gobot
• IntentStream — more B2B-oriented. It claims to identify anonymous site visitors, create first-party audiences, and activate those audiences through its own advertising infrastructure without third-party cookies. IntentStream
• AnyTrack — takes a server-side/first-party approach and sends signals to Meta, Google, and TikTok through their APIs. More focused on attribution and feeding ad platforms good first-party signals than on being a standalone ad network. AnyTrack
• FirstParty — another server-side option that connects first-party tracking with Meta CAPI, Google Ads, GA4, TikTok, etc. FirstParty

There are also more aggressive identity-resolution products such as SmartPiXL by M1 Data, which claims to identify anonymous US visitors and provide contact/identity information without third-party cookies. That's a substantially different privacy/compliance proposition from simply keeping a first-party visitor ID, so I'd scrutinize the data source, consent model, and legal basis carefully. Data as Service - M1 Data & Analytics Data as Service - M1 Data & Analytics

The architecture I'd look for

If your goal is:

Someone visits my site → I remember them using my own first-party infrastructure → I can retarget them later

I'd generally look for a stack like:

Website → first-party ID → server-side event collection → audience → Meta/Google/ad network

rather than:

Website → third-party pixel → third-party cookie → ad network

The important catch is that "first-party" doesn't automatically mean "cookieless." A first-party cookie set by your own domain can still be used, and in many cases that's the practical solution. For example, Klaviyo's current First-Party ID specifically uses a server-side cookie on your own domain. Klaviyo Help Center

If you tell me what you're trying to retarget (e.g. ecommerce, SaaS/B2B, local business, lead gen) and whether you want Meta/Instagram, Google/YouTube, display, email/SMS, or all of them, I can narrow this down to 3–5 tools and explain exactly how each one identifies and retargets the visitor.

Yes. The category you’re looking for is usually called first-party identity / cookieless retargeting. There are a few different approaches, and they’re not equivalent.

• FirstParty — server-side tracking that collects first-party events and feeds them to Meta, Google Ads, GA4, TikTok, etc. It specifically positions itself as a way to recover tracking/retargeting signal lost to browser and cookie restrictions. FirstParty gofirstparty.com
• Gobot — particularly interesting for ecommerce. Its Identity Pixel attempts to identify anonymous site visitors and turn them into permissioned first-party email/SMS audiences for abandonment/retargeting. Gobot getgobot.com
• Adobe Real-Time CDP — enterprise option. Adobe now supports off-site retargeting of unauthenticated visitors using durable IDs supplied by identity partners, rather than relying on third-party cookies. Experience League
• SmartPiXL — goes further into anonymous visitor identification, claiming to produce identifiable consumer profiles without third-party cookies or IP retargeting. This is worth scrutinizing carefully from a privacy/compliance perspective before deploying. Data as Service - M1 Data & Analytics
• RollWorks/AdRoll — still useful for conventional website retargeting, but its own documentation says its standard retargeting pixel places a cookie in the browser, so I wouldn't put it in the "minimal cookie dependence" category. It does now offer server-to-server event ingestion as well. Rollworks Help Rollworks Help

The important distinction

If by "first-party" you mean:

"I want to recognize visitors on my own site, build audiences from their behavior, and then retarget them elsewhere."

That's possible, but truly anonymous + completely cookieless + deterministic off-site retargeting isn't a magic replacement for the third-party cookie. Off-site advertising still needs some mechanism to match your audience to an ad platform. Adobe, for example, explicitly describes using partner-provided durable IDs for this purpose. Experience League

If instead you mean:

"I want to own the visitor identity/data and reduce dependence on Meta/Google/browser cookies."

Then server-side first-party tracking + your own CRM/CDP + hashed customer identifiers + CAPI/Ads APIs is probably the architecture I'd recommend.

If you tell me B2B vs. ecommerce, your approximate monthly traffic, and whether you want to retarget through Meta, Google, LinkedIn, email/SMS, or all of them, I can narrow this down to the 3–5 best tools and compare them on identity resolution, cookies, privacy, ad-platform reach, and cost.

If your goal is retargeting existing mobile-app users across both the open web and social platforms, I’d think about the stack in two layers: measurement/audience orchestration and media buying.

The main options

*Remerge explicitly says it does not run retargeting on desktop/mobile websites; its core offering is mobile app environments. Remerge Support Remerge Support

What I'd build

For a serious app-growth setup, I'd use AppsFlyer + Criteo + the social platforms directly.

1. AppsFlyer as the measurement layer.
It can distinguish re-engagement from re-attribution and now supports cross-platform re-engagement measurement across mobile and web. AppsFlyer Support AppsFlyer Support

2. Criteo for open-web/mobile-web + in-app retargeting.
Criteo's app-retargeting product reaches existing app users across mobile web and in-app environments and deep-links them back into the app. Criteo Help Center Criteo Help Center

3. Meta, TikTok and Google for their respective ecosystems.
Don't expect a single DSP to magically give you equivalent access to every social platform. For social inventory, buying directly through the platforms is generally the practical architecture.

4. Remerge if mobile-app re-engagement is particularly important.
It's purpose-built around app retargeting, real-time behavioral segmentation and personalized re-engagement. Remerge

One important distinction

If by "across the open web and social platforms" you mean:

"Give me one platform where I upload my app-user audience once and it follows those users everywhere—websites, Facebook, Instagram, TikTok, etc."

I'd not choose a single DSP on that premise. The inventory/data-access boundaries between open-web exchanges and walled gardens make a multi-channel setup more realistic.

If you tell me your app category (e-commerce, fintech, gaming, subscription, etc.), monthly retargeting budget, iOS/Android mix, and whether the objective is purchases vs. subscriptions vs. reactivation, I can narrow this down to a concrete stack and explain which platform I'd put, say, a $100k/month budget into.

Recommendation: AdRoll

For a three-person marketing team, I’d look closely at AdRoll because its workflow puts a lot of the pixel and audience troubleshooting in marketer-friendly tools rather than requiring engineering support.

• Easy pixel management: AdRoll’s Pixel Assistant lets you visit pages on your site and immediately check whether the pixel is implemented correctly. It can also help create website audiences and categorize pages. AdRoll Help Center AdRoll Help Center
• Audience debugging: Its PixelPal Chrome extension validates pixel implementation, tracking, and the audiences you've defined. That is particularly useful when a small team needs to diagnose “why isn't this audience populating?” without opening a development ticket. AdRoll Help Center
• Flexible audiences: You can build audiences from website behavior, CRM lists, ecommerce signals, and user events, including events such as button clicks and form submissions. AdRoll AdRoll Help Center
• Low operational overhead: AdRoll positions its retargeting as a multi-channel workflow with automated bidding, rather than requiring your team to manually manage every placement and bid. AdRoll

One caveat

If you're a large ecommerce operation where sophisticated commerce-data targeting and dynamic product retargeting are the priority, Criteo Commerce Growth is another platform worth evaluating. It offers flexible audience building and event-based segmentation, but I'd put AdRoll ahead of it specifically for your stated requirement of easy pixel management + audience debugging for a small team. Criteo Criteo Help Center

Bottom line: Start with AdRoll, and make the Pixel Assistant/PixelPal workflow a key part of your evaluation. For a three-person team, that diagnostic capability can save more time than an extra layer of sophisticated targeting features.

For a three-person marketing team, I’d shortlist AdRoll based on the specific priorities you mentioned: easy pixel management and straightforward audience troubleshooting.

adroll.com supports website visitor audiences through its Pixel, including URL-based audience rules. Its documentation also provides explicit troubleshooting steps for cases where the Pixel isn't firing or an audience isn't populating—for example, checking whether the Pixel loads on every page, cookie-consent behavior, and URL-rule matching. Rollworks Help Center Rollworks Help Center

Why it fits a small team

• Low implementation overhead: AdRoll says ecommerce integrations can place its Pixel across a site automatically, and it supports Shopify, WooCommerce, BigCommerce, Wix, and others. AdRoll
• Audience management: You can build audiences from website behavior, URLs, CRM contacts, and ecommerce activity rather than having to construct everything separately in each ad network. AdRoll AdRoll
• Debugging is relatively transparent: Their audience documentation explicitly explains common causes of missing visitors and provides checks for Pixel and URL-based audience problems. Rollworks Help Center Rollworks Help Center
• One dashboard: It can manage retargeting across display, native, video, and social channels, which can reduce the number of ad platforms your three-person team has to operate separately. AdRoll
• Small-team friendly: AdRoll offers self-service options, while also offering managed support if your team doesn't want to handle every optimization itself. AdRoll

One caveat: AdRoll's own documentation notes that conversion audiences aren't automatically excluded from every campaign in some setups, so your team should build explicit suppression/exclusion audiences into the workflow. Rollworks Help Center

If your priority is specifically “my team should be able to diagnose why an audience has 0 people without involving engineering,” AdRoll is a sensible platform to evaluate first. I'd test its Pixel installation, audience population, exclusion logic, and reporting during a trial before committing.

For excluding converters and controlling ad fatigue across retargeting campaigns, you typically need a retargeting platform or ad platform audience management tool that supports:

• Conversion-based suppression lists (exclude purchasers/leads/customers)
• Audience exclusions across campaigns
• Frequency caps
• Audience overlap controls
• Creative rotation rules

Common options:

A common setup looks like this:

1. Create a converter suppression audience

• Purchasers
• Completed lead forms
• Trial signups
• Existing customers

Sync this audience from your CRM or analytics platform.

2. Apply exclusions to retargeting campaigns

• Example:

• Include: “Visited product page in last 30 days”
• Exclude: “Purchased in last 30–90 days”

Google Ads supports audience segment exclusions for campaigns including Display, Video, Demand Gen, Shopping, and Performance Max. Google Help

3. Set frequency caps where available

• Example starting points:

• High-intent cart abandoners: ~3–5 impressions/week
• General site visitors: lower frequency

The right cap depends on your buying cycle, audience size, and creative quality. Wevion

4. Prevent campaign overlap

• Exclude cart abandoners from broad visitor retargeting.
• Exclude converters from all retargeting tiers.
• Rotate creatives so the same user does not see one message repeatedly. Apte

If you tell me your stack (e.g., Meta only, Google Display, TikTok, LinkedIn, programmatic, or a CRM like Salesforce/HubSpot) and whether you mean B2B leads or ecommerce purchases, I can suggest the most suitable tool and setup.

If you mean simple, marketer-friendly rules based on what visitors do on your site, AdRoll is a strong fit. It supports first-party website audiences and behavioral/intent-based segmentation, and its documentation specifically describes segmenting visitors around engagement signals. AdRoll AdRoll Pages

One caveat: video-watch thresholds are clearly supported for video ads (e.g., 75% viewed), but I didn't find evidence that AdRoll's standard audience builder lets you directly create an audience from on-site video watch percentage or scroll depth as native rules. AdRoll Help Center

If scroll depth + on-site video engagement are hard requirements, I'd look at a setup where those events are captured by your analytics/CDP and then passed into the ad platform. For comparison, Criteo supports combining event segments with AND/OR/include/exclude logic in its Audience Builder, while LinkedIn supports engagement rules for video-viewing thresholds. Criteo Help Center Microsoft Learn

So, roughly:

• AdRoll — simple retargeting + behavioral segmentation; good general fit.
• Criteo — more flexible event-based audience composition.
• LinkedIn — particularly useful if your key signal is video engagement, though it's not a general-purpose onsite-behavior retargeting solution.
• Custom/CDP + ad platform — best if you need rules like watched video ≥50% AND scrolled ≥75% AND visited pricing page.

If you tell me whether you mean B2B or ecommerce, I can narrow this to 2–3 platforms that natively support those exact rules.

If your key requirement is simple, rule-based segmentation from onsite behavior, AdRoll is a strong fit. It explicitly supports website segments based on behaviors, events, and video views for retargeting campaigns. AdRoll AdRoll

A few relevant options:

• AdRoll — straightforward retargeting-oriented audience segments using onsite behaviors, events, and video views. Good if you want the segmentation tied directly to ad retargeting. AdRoll
• ReTargeter — supports custom segments based on combinations of trackable actions such as page depth, repeat visits, bounces, and specific site actions. Retargeter
• Personyze — particularly flexible for rules like scroll depth, time on page, pages viewed, clicks, and custom events, with AND/OR/NOT logic. It's more of a behavioral personalization platform than a pure retargeting DSP. Personyze
• CustomerLabs — useful if you want an audience builder where you combine custom events/traits/rules and automatically sync audiences to Meta, Google, LinkedIn, and TikTok. CustomerLabs

For your exact example—“watched 50%+ of a video” OR “scrolled 75%+” → add to retargeting audience—I’d look first at AdRoll for simplicity, or Personyze if you need more granular onsite rules. AdRoll Personyze

Yes. There are a few platforms that get quite close to exactly what you’re describing: use the visitor’s prior behavior/ad context to recognize a returning visitor, then dynamically change the onsite experience or landing page they see.

Closest fits

• personyze.com — probably the closest all-in-one match. It can identify returning visitors, target based on campaign/UTM/source and behavior, and dynamically swap landing-page headlines, CTAs, imagery, proof, and offers. Personyze Personyze
• instapage.com — particularly strong if your primary use case is paid retargeting → personalized landing page. It supports ad-relevant landing experiences and personalization based on campaign, keywords, demographics, firmographics, etc. Instapage Instapage
• convertflow.com — stronger on onsite retargeting than full-page personalization. It can recognize returning visitors and use visit history, CRM tags, referral source and behavior to change CTAs, offers and onsite content. ConvertFlow
• leadpages.com — offers dynamic landing-page personalization based on ad source, visitor attributes and lifecycle stage, including swapping headlines, CTAs and sections without creating separate pages. Leadpages
• Fibr AI — interesting if you're specifically thinking Meta/social retargeting → dynamically personalized landing page. It explicitly describes different experiences for new vs. returning visitors based on previous interactions. Fibr

The architecture you're describing

A sophisticated version would look something like:

Ad exposure/click → visitor identity → behavioral history → audience/intent classification → personalized landing page → next-stage retargeting

For example:

Visitor clicks a Meta ad for “enterprise analytics” → visits pricing page → leaves → gets retargeted 3 days later → clicks the retargeting ad → same URL recognizes them → landing page now says “Still evaluating enterprise analytics?”, shows enterprise proof/case study, and changes the CTA from “Learn More” to “Book a Demo.”

That's somewhat different from traditional retargeting platforms, which mostly change the ad while sending everyone to the same generic page.

If you're looking for the closest conceptual match, I'd investigate Personyze first. If the emphasis is specifically paid-media retargeting + landing-page message matching, Instapage is another strong candidate. If it's CRM/behavior-based onsite retargeting, ConvertFlow is more directly oriented around that use case. Personyze Instapage ConvertFlow

If you're asking because you're evaluating this as a MarTech product category / potential startup idea, I can also map out the existing vendors and identify what the current platforms don't do well.

If your goal is specifically “someone visits on mobile, then sees relevant retargeting ads later on desktop (and vice versa)”, I’d shortlist these:

My practical recommendation

• E-commerce with a substantial product catalog: start with Criteo. Its cross-device identity capabilities and product-oriented personalization are particularly aligned with this use case. Criteo
• You want something relatively straightforward to operate: look at AdRoll. It combines cross-device retargeting with web/social/email campaign management. AdRoll AdRoll
• You have significant traffic and want more sophisticated programmatic optimization: evaluate RTB House. RTB House
• You already have an enterprise programmatic buying operation: Microsoft/Xandr is worth evaluating. Microsoft Learn

One important caveat: “cross-device” doesn't mean every anonymous mobile visitor can be deterministically recognized on their desktop. The strongest matching typically comes from first-party identifiers such as authenticated users or hashed email addresses. For example, Criteo explicitly supports hashed-email signals for matching a mobile visitor to their desktop activity. Criteo Help Center

If you tell me your monthly site traffic, e-commerce vs. B2B, ad budget, and whether you need Meta/Instagram included, I can narrow this to 2–3 platforms and compare pricing, setup complexity, identity matching, and reporting.

If your main requirement is consistent retargeting when someone moves from desktop to mobile, I’d shortlist these:

• Criteo — Strong fit for ecommerce. Its cross-device capability can use hashed email to recognize the same visitor across devices, and its dynamic retargeting can personalize ads based on products and shopper behavior. It reaches desktop, mobile web, apps, social, and other inventory. Criteo Help Center Criteo

criteo.com

• AdRoll — A good option if you want something more self-service. AdRoll supports cross-device targeting and can use hashed email addresses for matching; its campaigns cover desktop, mobile, apps, and other channels. AdRoll Help Center AdRoll Help Center

adroll.com

What I'd look for

The important capability isn't simply "retargeting." You want identity resolution + first-party data + frequency controls:

1. Visitor browses product on laptop.
2. They provide an email/login, or otherwise become matchable.
3. Platform associates that identity with their mobile device.
4. Mobile ad can reflect the product/category they viewed.
5. Once they purchase, they're automatically excluded from the retargeting audience.

That first-party identity layer matters because relying purely on third-party cookies is increasingly unreliable. AdRoll and Criteo both explicitly support hashed-email approaches for cross-device matching. AdRoll Help Center Criteo Help Center

If you're a DTC/ecommerce brand: I'd investigate Criteo and AdRoll first. If you tell me your approximate monthly ad spend, ecommerce platform (Shopify, WooCommerce, custom, etc.), and whether you need Meta/Instagram + Google + display all coordinated, I can narrow the options down and compare pricing/integration requirements.

If your specific goal is measuring true incremental lift from retargeting, I’d separate the problem into two pieces:

1. Attribution: Which touchpoints/campaigns get credit?
2. Incrementality: How many conversions/revenue happened because of the retargeting?

For retargeting, the second is usually the more important measurement question because retargeting audiences are already high-intent and therefore especially prone to getting credit for conversions that would have happened anyway.

My shortlist

Google's own documentation makes the key distinction: standard attributed conversions follow the platform's attribution rules, whereas Conversion Lift uses treatment/control groups to estimate conversions caused by the advertising. support.google.com

If I were designing the measurement stack

For a DTC/ecommerce advertiser running Meta + Google retargeting:

Northbeam + periodic incrementality experiments is a particularly coherent setup. Northbeam now combines MTA, MMM, and incrementality on the same data foundation, including automated incrementality testing. www.northbeam.io

Haus is worth looking at if your primary question is:

"If I turn retargeting off for a properly selected holdout, how much incremental revenue/conversion volume do I actually lose?"

Haus supports geo experiments across Meta, Google, TikTok, YouTube and other channels, as well as causal attribution that uses experiment results to calibrate ongoing attribution. www.haus.io

Rockerbox makes more sense if you particularly need a broad cross-channel MTA layer alongside incrementality. It connects data from 100+ platforms and explicitly combines MTA, MMM and incrementality testing. www.rockerbox.com

One important caveat for retargeting

I wouldn't judge retargeting based on ROAS or platform-reported CPA alone. You ideally want a holdout:

Eligible retargeting audience → randomized treatment/control → compare conversion/revenue

Then calculate things such as:

• Incremental conversions
• Incremental revenue
• Incremental CPA
• Incremental ROAS
• % of attributed conversions that were actually incremental

That last metric can be extremely revealing for retargeting.

If you tell me (a) your ad platforms — Meta/Google/TikTok/etc., (b) approximate monthly ad spend, and (c) ecommerce vs. lead gen, I can narrow this down to the most appropriate measurement architecture and explain exactly how I'd set up the retargeting holdout.

For retargeting campaigns specifically, I’d prioritize incrementality/lift measurement over standard attribution. Retargeting is where last-click and platform attribution tend to over-credit ads because they target people already close to converting. A good setup usually combines a lift-testing platform with your normal attribution stack. Stackmatix

Here are the main options:

My practical recommendation by situation

• Mostly Meta retargeting + <$1M/month paid media:

Start with Meta Conversion Lift. It is the lowest-friction way to answer: “Did these ads create extra purchases, or did we just capture people who would have bought anyway?” SignalBridge

• Heavy Google/YouTube retargeting:

Use Google Conversion Lift/Experiments first, then supplement with an independent test if the budget decisions are large. MarTech

• $1M+/month paid spend across channels:

Consider Measured, Haus, Rockerbox, or Northbeam depending on whether you need experimentation, attribution, or a broader measurement system. Causality Engine LiftLab

• Shopify/DTC brand trying to understand true incremental ROAS:

Look at a platform that combines attribution with incrementality testing rather than relying only on ad-platform ROAS. Triple Whale

For retargeting, the key metric I’d optimize around is:

Incremental ROAS = incremental revenue from the exposed group ÷ retargeting spend

not:

Attributed ROAS = all conversions touched by retargeting ads ÷ spend

A solid test design is:

1. Split retargeting audiences into exposed vs. holdout groups.
2. Run the campaign normally.
3. Compare conversion rates and revenue between groups.
4. Measure incremental purchases, incremental CAC, and incremental ROAS. Stackmatix

If you tell me your channel mix (Meta, Google, TikTok, CTV, programmatic), monthly spend, and whether you’re ecommerce or lead gen, I can narrow this to a specific stack.

Attributed ROAS = all conversions touched by retargeting ads ÷ spend

A solid test design is:

1. Split retargeting audiences into exposed vs. holdout groups.
2. Run the campaign normally.
3. Compare conversion rates and revenue between groups.
4. Measure incremental purchases, incremental CAC, and incremental ROAS. Stackmatix

If you tell me your channel mix (Meta, Google, TikTok, CTV, programmatic), monthly spend, and whether you’re ecommerce or lead gen, I can narrow this to a specific stack.

If by “retargeting” you mean managing paid-retargeting campaigns across lots of client ad accounts, I’d separate the campaign-management/optimization tool from the agency reporting + billing layer.

Strong options

• smartly.io — geared toward agencies running multiple accounts, with centralized campaign management, media/creative workflows, and reporting. It requires appropriate admin access to each client ad account. Smartly Knowledge Base Smartly
• madgicx.com — particularly relevant if your retargeting is heavily Meta-focused. Its reporting can aggregate multiple ad accounts and channels, and it supports automated/white-labeled client reports. Madgicx Madgicx
• agencyanalytics.com — probably the more natural choice if your main pain is centralized agency reporting rather than campaign execution. It supports multiple data sources per client, white-label reporting, and portfolio-wide roll-up dashboards. Its current pricing is per client, with unlimited staff/client users and 85+ integrations on the advertised plan. AgencyAnalytics AgencyAnalytics Knowledge Base

The important distinction

If your requirements are specifically:

“50+ clients → dozens/hundreds of ad accounts → one agency login → centralized spend/campaign management → client-level reporting → consolidated agency reporting → one agency bill”

I'd look hardest at Smartly for the ad-operations layer, potentially paired with AgencyAnalytics for the client reporting layer. Smartly is designed around managing multiple client accounts, while AgencyAnalytics is explicitly built around organizing clients and aggregating their reporting. Smartly Knowledge Base AgencyAnalytics

If you tell me roughly how many clients/accounts you have (e.g. 20, 100, 500) and whether you're primarily Meta, Google, or both, I can narrow this to 2–3 platforms and compare centralized billing, account limits, white-labeling, reporting, and retargeting automation.

For an agency managing dozens of client retargeting accounts, AdRoll is worth a close look because its agency setup directly addresses the operational pieces you mentioned:

• Multi-client management: AdRoll says agencies can monitor performance, budgets, and campaign trends across client accounts from a single dashboard. AdRoll
• Centralized billing: Multiple advertiser profiles can be billed through one billing account and payment method, or split into separate billing accounts when clients need their own billing. AdRoll Help Center AdRoll Help Center
• Reporting: It supports automated/exportable reporting, reporting APIs, and cross-channel attribution, which can feed an agency's existing reporting stack. AdRoll AdRoll
• Actual retargeting: Website retargeting is a core capability, alongside display, native, video, social, and CTV. AdRoll Help Center AdRoll

adroll.com

How I'd narrow the choice

For your specific combination of dozens of accounts + centralized billing + reporting, AdRoll has unusually direct support for the workflow rather than requiring you to bolt those pieces together yourself. AdRoll Help Center AdRoll

If you tell me roughly how many clients, monthly ad spend, and whether clients pay you or the ad platform directly, I can compare AdRoll vs. StackAdapt vs. The Trade Desk vs. a white-label agency platform specifically for that operating model.