Retail media buyers in Europe have changed what they ask sellers to prove, and the sellers have answered with plans. Before any 2027 budget goes up, I would turn those plans into dated deliverables in the contract.
IAB Europe’s third Attitudes to Retail Media report, published November 3, draws on 150 buy-side and sell-side respondents. Its numbers describe a market that is spending more and trusting less. 71% of European buyers have partnered with retailers for over a year, up from 51% in 2024. Yet only 12% call their retail media strategies fully sophisticated, and 61% name a lack of measurement and reporting as a leading barrier to investment. Concern about data availability rose from 31% to 58% in a year.
The ask has moved past ROAS
ROAS was chosen as a desired measurement metric by 49% of European buyers, down from 89% in 2025. Buyers now prioritize unified online and offline reporting at 66%, new-to-brand or new-to-category measurement at 63% and incrementality at 57%. Sellers have not matched that. 58% of buyers want multi-touch attribution, and 31% of sellers offer it.
Jason Wescott, Global Head of Commerce Solutions at WPP Media and chair of IAB Europe’s Retail & Commerce Media Committee, put the commercial stakes plainly in the release: “retailers who crack advanced measurement stand to win the lion’s share of budgets.” I agree with the direction and disagree with the timing. The budget decision comes first, and the measurement arrives later, if at all.
A plan is not a capability
The report’s encouraging line is that 63% of sellers plan to enhance their measurement capabilities in the next 12 months. That is a statement about intent, and a buyer who commits 2027 money against it is financing the roadmap. The same sellers also report that 68% plan to build AI-powered campaign management, and 50% plan capabilities for agentic commerce and conversational AI discovery. Measurement competes for the same engineering time.
Marie-Clare Puffett, senior director of industry development and marketing at IAB Europe, said there is still “work to do to build buyer confidence” and pointed to the group’s Commerce Media Measurement Standards and Retail Media Certification Programme as the route. Those are useful, and they are voluntary for a seller to adopt.
The strongest counter-argument
Buyers can say they have no leverage. Retail networks hold first-party purchase data, 73% of buyers increased investment over the past 12 months, and a network that offers only ROAS is still the only place to reach its shoppers. Asking for incrementality tests as a condition may simply move budget to a rival network that asks for nothing.
That is true for the largest networks, and it is a reason to be specific rather than demanding. A buyer does not need every network to deliver multi-touch attribution. A buyer needs the network to commit to one named measure by a date, and to say what happens if the date passes.
There is a second reason to put dates in writing. The jump in data availability concerns, from 31% to 58%, points at the same constraint. A seller that cannot share the data needed to test a result will not be able to deliver incrementality either, because an incrementality test needs the exposed and unexposed groups. A date for the test is therefore also a date for data access, and buyers should ask for both in the same clause.
What I would write into the 2027 agreement
Three terms cover most of the gap in the data. First, name the incrementality method, whether holdout or geo test, and the quarter it becomes available. Second, require new-to-brand reporting at the same grain as the sales report, so the 63% of buyers who want it can reconcile the two. Third, tie the second half of the annual commitment to delivery of the first two. Our earlier piece on asking a loyalty vendor for offer relevance next to scan rate made the same case for a different retail tool, and the IAB’s own cross-channel measurement decision guide gives buyers vocabulary for the method choice. Retail ad revenue is now large enough to price in public filings, as our report on DoorDash’s agreement to acquire Instacart showed with the $331 million of ads and other revenue Instacart reported, and the contract language around it should be as exact as the revenue line.
If a network refuses all three, a buyer holding the 2027 budget has learned something about the roadmap before paying for it.
Source: IAB Europe, Attitudes to Retail Media Report 2026 press release
