Solving for closed-loop attribution with commerce media

Key takeaways

• Commerce media spending is growing, but the ecosystem remains fragmented.
• Closed-loop measurement is the core value proposition of commerce media, but how you access it depends on your existing stack.
• The right approach depends on which retailers matter to your brand, how your media ecosystem is structured, and what data you can actually access.
• This post takes a look at three commerce media strategies: Google’s Commerce Media Suite, Amazon Marketing Cloud, and MediaMath (Infillion).

Commerce media is one of the fastest-growing channels in digital advertising, but it’s also one of the most fragmented.

According to EMARKETER, US commerce media ad spending is forecast to reach $83.71 billion in 2026 and account for nearly a quarter of all digital ad spending by 2030. Retail media remains the largest and most mature slice of that ecosystem, accounting for 85.8% of all commerce media spending in 2028.

But the premise of commerce media — using a retailer's first-party purchase data to reach high-intent shoppers and measure whether they bought — plays out very differently across multiple platforms and retail data partners. Closed-loop attribution still depends heavily on which networks you're buying through, which retailers you're working with, and how your existing stack is set up.

Having worked with brands and agencies across each of these platforms, we've found the conversation almost always starts with the same question: which platform is the right choice? The answer is rarely black and white. Each platform delivers a compelling set of capabilities, with unique advantages and tradeoffs. The right fit ultimately depends on your business objectives, data strategy, and organizational needs.

How commerce media measurement works across platforms

Commerce media creates a direct link between ad exposure and purchase. By leveraging retailers' first-party transaction data, brands can connect media investments to actual sales, enabling more accurate measurement, optimization, and attribution.

That's the promise, at least. In practice, the signal lives in different places depending on the retailer, and accessing it requires working through the platform that has a data relationship with that retailer. Display & Video 360 (DV360) has agreements with Walmart, Kroger, Albertsons, Costco, Best Buy, and others. Amazon Marketing Cloud has Amazon's own transaction data. MediaMath, powered by Infillion, brings in Catalina's deterministic in-store and receipt data across a broad set of retail media networks that aren't yet part of Google's or Amazon's ecosystem.

The retailers you sell through, the audiences you need to reach, and the platforms already in your stack all shape which path makes the most sense. And so does where you are in your commerce media journey. Brands new to commerce media are typically focused on launching campaigns and establishing a strong operational foundation. As their programs mature, the focus shifts toward measuring incrementality, understanding cross-channel attribution, and incorporating commerce signals into marketing mix models.

What Google's Commerce Media Suite offers brands already on GMP

Google Marketing Platform (GMP) has become one of the most capable commerce media environments available, and the retail data integrations it has added in recent years are among the strongest reasons to consider it. The native path to commerce media runs through two tools:

• Display & Video 360 for programmatic activation
• Search Ads 360 (SA360) for on-site search at the advertiser level

Google's Commerce Media Suite now includes retail data from over 30 partners across Display & Video 360, Google Ads, and Search Ads 360. For instance, Kroger Precision Marketing provides high-intent, first-party audience data across YouTube, with SKU-level reporting that connects display and YouTube ad exposure to Kroger sales outcomes.

More recent additions to the Commerce Media Suite include Best Buy, Shipt, and Walmart Connect. Google has also added Demand Gen as an available campaign type within Commerce Media Suite, allowing brands to activate retailer first-party data across YouTube, Discover, and Gmail, then measure those campaigns against downstream sales.

On the search side, Search Ads 360 now supports on-site retail media activation through a centralized management hub, with integrations for sponsored product inventory across Criteo and Koddi. This gives brands a single interface for managing how products appear and perform across retailer websites, plus standard search and Performance Max campaigns, with cross-retailer performance reporting built in.

The off-site component uses Conversions with Cart Data to optimize toward moving specific brand SKUs rather than generic retailer conversions. Retailers like Roundel (Target's retail media network) can now connect online, app, and offline sales data to Performance Max campaigns through Search Ads 360, giving brands a cleaner read on total retail impact rather than just digital conversions.

The Google Marketing Platform path makes the most sense for brands who:

• Want commerce media measurement consolidated in a single platform
• Have key retail partners in Google's network, including Kroger, Walmart, Albertsons, Best Buy, or Costco
• Are prioritizing YouTube as a commerce media activation surface
• Are already running Display & Video 360 or Search Ads 360, or evaluating either as a primary buying platform

Amazon Marketing Cloud use cases for full-funnel commerce media measurement

For brands with significant Amazon presence, Amazon Marketing Cloud (AMC) offers a measurement environment that few platforms can match in terms of transaction data depth. It provides event-level data across Amazon DSP campaigns running across Amazon.com, Amazon Fresh, and Whole Foods Market, and connects Amazon Ads signals with advertiser first-party data and third-party datasets for custom analysis.

Rather than relying on Amazon's standard reporting, Amazon Marketing Cloud lets practitioners build custom queries to answer specific business questions like:

• Which Sponsored Products and DSP campaigns are working together to drive conversion, and which are cannibalizing each other?
• What share of my Amazon sales this quarter came from customers who had never bought my brand before?
• At what ad frequency does my DSP audience stop converting?

Amazon DSP campaigns can also be measured against outcomes that include in-store conversion and omnichannel impact beyond Amazon-side sales. Beyond measurement, Amazon Marketing Cloud also opens up audience segments you can't build in standard campaign setup — like suppression lists, cart abandoners, and high-value lookalikes — that activate directly through Amazon DSP.

Note that Amazon Marketing Cloud doesn't replace Google Marketing Platform measurement. Instead, it operates as a parallel environment for Amazon-specific campaigns. So if Amazon is a core retail channel for your company but you also have a heavy Google presence, it often makes sense to run both together.

Commerce media measurement for the open internet

There are instances where these ecosystems don't cover the retailers you care about most, or where you need measurement that spans partners across the open internet.

Infillion MediaMath provides a commerce media approach for those exact use cases. Its agnostic identity infrastructure connects across RampID, UID2, and its own ConnectedID, layering in modeled signals to reach audiences that wouldn't show up in a clean match alone. It's also built with regulated industries in mind, with privacy-forward targeting baked in.

The integration of Catalina, alongside Arrival, Infillion's foot traffic measurement tool, significantly strengthens this offering. Catalina brings in-store and receipt-level attribution across a network of 70 retail banners, including partners not yet integrated into Google's commerce media suite. Pairing Arrival's location-based attribution with Catalina's receipt-level data gives brands deep historical purchase insights across both physical and digital touchpoints. That log-level data can also feed directly into marketing mix models (MMM), which matters for brands building MMM inputs from direct commerce-side signals rather than reconstructing them from point-of-sale access alone.

The integration between Catalina data and broader Google Marketing Platform workflows is still developing. Brands currently using Google Marketing Platform as their primary ad server should evaluate where the MediaMath pixel fits into their tracking architecture.

Choosing between commerce media platforms based on your existing stack

As you can see, there’s no need to pick just one commerce media path. Consider these questions when evaluating which platform (or platforms) makes the best sense for your company:

Which retailers matter most to your brand?

Your platform's retailer relationships largely determine your options, so starting with the retailers that matter most to your brand is the right place to begin.

Where is your media activation today?

If you're already running Display & Video 360 as your primary demand-side platform, adding Commerce Media Suite carries a relatively low incremental lift. The data connections and SKU-level reporting pipe into the infrastructure you already own. If you're working with multiple demand-side platforms or your activation is Amazon-centric, you may want to consider a different path.

What does your measurement architecture support?

Closed-loop measurement requires a clean data path from ad exposure to purchase signal. Find out where your tracking has gaps before building your strategy around any of these tools. Path-to-conversion reporting is one way to surface those gaps and make the full customer journey visible.

Building a commerce media strategy that fits your stack

As commerce media keeps evolving, the platform landscape will continue to shift. Future growth depends less on budget intent and more on whether buyers have the tools, knowledge, and infrastructure to execute and optimize across channels. Knowing where your data actually lives — and which platforms have access to it — is the right starting point.

If you're answering these questions for your brand or clients, Adswerve works across Google Marketing Platform, Amazon, and ecosystem-agnostic environments to help teams build commerce media strategies that fit their actual stack. We'd love to talk through where to start.