The short answer
Most retail media is measured by the network that sold it, usually as last-touch return on ad spend. That shows attributed sales, not what changed in shoppers’ minds. To measure the brand effect, compare verified shoppers who saw the retail media with a matched control on a brand KPI fixed in advance, run by someone independent of the network.
Key takeaways
- UK retail media reached £3.7bn in 2025, up 17.5%; global spend is forecast at $200.4bn in 2026.
- Most networks report last-touch ROAS, which credits sales that might have happened anyway.
- The IAB and MRC call for transparent incrementality methods; experiments are the gold standard.
- Brand lift complements ROAS by showing what retail media did to consideration and perception.
A fast-growing channel that marks its own homework.
Retail media is one of the fastest-growing channels in advertising. AA/WARC figures put UK retail media at £3.7bn in 2025, up 17.5% on the year, and WARC Media forecasts global retail media ad spend of $200.4bn in 2026. Yet the default outcome on most networks is last-touch attribution reported as return on ad spend: the network sells the ad, owns the shopper data, sets the attribution window and reports the result.
Buyers have noticed. An IAB report found 62% of buyers considered the lack of measurement standards a major obstacle to advertising on retail media networks.
What the standards say.
The IAB and Media Rating Council’s Retail Media Measurement Guidelines, finalised in January 2024, set out how networks should measure and disclose, including how incrementality is measured. The IAB and IAB Europe’s commerce media guidance from November 2025 treats experiment-based approaches, such as randomised control tests and matched markets, as the gold standard for proving causal lift.
Why ROAS misses the brand.
Les Binet and Peter Field’s work on the IPA Effectiveness Databank found that the most effective campaigns balance brand building and sales activation, roughly 60:40. Retail media is mostly measured as activation. If the only number is attributed sales, nobody knows whether the spend also changed how shoppers see the brand, which is what supports future sales and price.
How to measure the brand effect of retail media.
- 1Fix one brand KPI before the campaign, such as consideration, price perception or preference against named competitors.
- 2Screen for the shoppers who matter, such as recent category buyers or a retailer’s shoppers.
- 3Recruit exposed shoppers from the media where you can, with QR codes in store or on site, and confirm exposure with recognition and a decoy ad.
- 4Build a matched control from the same audience and period who weren’t exposed.
- 5Size the sample to the smallest lift worth detecting, and report the full-sample lift with its 95% range.
- 6Keep the evidence: raw data, exclusions with reasons and a trace from each number to its source.
Questions
Isn’t retail media incrementality the same as brand lift?
No. Incrementality studies usually measure extra sales caused by the ads. Brand lift measures changes in what shoppers think, such as consideration or price perception. Both use exposed and control groups, but they answer different questions.
Can I compare retail media networks on brand effect?
Yes, if the same independent method is used across them. Network-reported results use different data, windows and definitions, so they are hard to compare directly.
Sources
- Digiday: UK brands spend more on retail media (AA/WARC figures)
- invidis: Global retail media ad market forecast to top $200bn in 2026 (WARC Media)
- Chain Store Age: Looking beyond lift testing in retail media
- EMARKETER: IAB and MRC propose retail media measurement standards
- IAB/MRC Retail Media Measurement Guidelines (January 2024)
- PPC Land: IAB releases measurement framework for commerce media campaigns
- IPA: The Long and the Short of It (Binet and Field)