Is Your Retail Media ROAS Measuring Performance or Just Shelf Access?
Media buying on retail marketplaces is increasingly automated. Bidding is optimized in real time by the retailer's own algorithms. Reporting, on the other hand, comes down to a single number: the ROAS the platform hands you.
What's less clear is what that number actually measures. For a meaningful share of retail media spend, the answer isn't ‘advertising performance.' It's 'the cost of being on the shelf.' And the gap between the two can represent hundreds of millions of dollars in misinformed allocation decisions.
Retail media is about to cross $200 billion. Not all of it is advertising performance
WARC forecasts that global ad investment on retail media networks (RMNs) will top $200 billion by 2027. In several markets, that line item is already on track to surpass combined linear and connected TV investment as early as 2026 (article in French).
The growth logic is compelling on paper: reach high-intent shoppers at or near the point of purchase, using the retailer's own first-party data. Amazon and Walmart Connect are the most visible examples, but the ecosystem now spans more than 200 retail media networks worldwide.
The problem is that this category bundles two fundamentally different types of spend under a single label. Some retail media investment is genuine performance advertising: targeted, measurable, and optimizable. Some of it is closer to a cover charge, the cost of visibility on a retailer's platform, regardless of whether that visibility drives an incremental sale. Measuring both through the same ROAS lens doesn't just produce imprecise numbers. It produces numbers that are structurally incapable of informing a real allocation decision.
Why this was hard to solve and why it isn't anymore
Isolating the true incrementality of a retail media placement, separate from organic demand, requires two things that have long been missing: clean categorization of the spend, and a testing method capable of producing causal truth.
The first obstacle is budgetary and organizational. Retail media sits at the overlap of trade marketing, sales, and brand marketing, three functions that often compete for credit using incompatible metrics. Sales claims the retailer relationship, marketing measures media ROI, and trade tracks distribution costs, each operating from its own version of the truth. Folding trade investment and media investment into a single line and then running both through the same measurement framework is one of the most common causes of artificially inflated retail media ROI.
The second obstacle is methodological. Without a reliable causal test, retailer-reported ROAS remains the only data available, despite its structural bias.
Two developments have changed this:
- The wider adoption of Matched Market Testing (MMT), controlled experiments run across comparable markets where some receive the ad while others don't, producing a defensible causal truth.
- The maturity of Marketing Mix Modeling, now capable of ingesting those validated incrementality estimates into a full-funnel view, held to the same rigor as any other media lever.
For the first time, retail media can be measured against the entire business, not just against the metrics the retailer chooses to report.
What the data reveals and where the blind spot still sits
Three findings stand out, and each carries a direct implication for budget allocation.
Fragmentation is as much a measurement problem as an operational one
With more than 200 retail media networks, each operating as a walled garden with its own proprietary metrics, building a coherent cross-network view of performance is a challenge before it's even a modeling question.
Retail media's footprint is expanding faster than its measurement
The perception of a purely lower-funnel, sponsored-search channel is becoming outdated. The most advanced RMNs are expanding into connected TV, social platforms, and in-store digital screens, all still tied back to the retailer's first-party data. Walmart Connect's partnerships with Roku and TikTok, and Amazon's integration of Prime Video ads into its DSP, are concrete examples. Every expansion of scope widens the blind spot if measurement doesn't keep pace.
Viewability is an underused signal inside retail media
Media quality within retail media remains a largely underused signal. Viewability (whether an ad was actually seen) is one of the few quality signals retail media networks can report against a consistent third-party standard.
An Integral Ad Science (IAS) observational analysis of a CPG brand's Q1 2023 campaign found that in-view ads delivered a 200% lift in conversions and a 268% lift in ROI — the equivalent of an additional $2.25 return for every dollar spent.
How Ekimetrics measures what retail media actually produced
The question we ask every CPG client entering retail media measurement is simple: are you measuring what you spent or what it did? Most are doing the former, tracking platform-reported ROAS against the full retail media budget, shelf access fees included, with no link to actual advertising performance.
Our approach runs in three steps.
- Clean categorization of spend: separating genuine media investment from shelf access, before any modeling happens. No model, however sophisticated, can produce an actionable number from uncategorized spend.
- Causal truth via Matched Market Testing: isolating the real incremental lift, distinct from demand that would have materialized anyway.
- Full-funnel MMM integration: feeding those validated incrementality estimates into a Marketing Mix Model, letting Sales, Trade, and Marketing teams evaluate retail media against every other business driver, not through each silo's self-reported metrics.
The output isn't just a more accurate ROI figure. It's a reallocation signal: which placements are genuinely incremental, which retailers deliver real lift, and where the next dollar should go.
Retail media is a powerful lever as long as you separate what it buys from what it proves
Retail media isn't a channel to pull back from. It's one of the most structurally important growth levers in today's CPG budget. The question isn't whether to keep investing; it's knowing which share of that investment is generating real incremental value, and which share is simply paying for visibility.
Brands that measure this lever properly don't just get cleaner reporting. They negotiate from a position of evidence rather than instinct, with every retailer, on every line of budget. The ROI is measurable. The methodology exists. What separates most marketing leaders from a truly optimized retail media allocation is spend categorization and a causal measurement framework, not more data.
Want to see what your retail media spend is actually delivering, beyond what the retailer tells you? Talk to our team about building a measurement framework that separates signal from noise.
