Closed-loop isn't incremental. Four questions for every retail media network.
I used to report closed-loop ROAS from inside a retail media network. Here is what I would ask that network now that I sit on the brand's side.
At the Albertsons Media Collective, my team reported 3.0x+ average partner ROAS through closed-loop attribution: we could see the ad exposure and the purchase in the same dataset. That is a real advantage of retail media. It is also not the same thing as proof that the media caused the sale.
Closed-loop tells you who saw an ad and later bought. Incrementality tells you how many of those people would not have bought without it. On a loyal shopper base, that gap can be most of the number.
1. Ask for the window before the campaign, not after.
The IAB and MRC retail media measurement guidelines say attribution windows "must be disclosed before campaign execution and measurement." A 14-day window and a 30-day window can produce very different ROAS on the same flight. Agree the window in writing, use the same one across networks, and stop comparing numbers that were counted differently.
2. Ask for a holdout, and ask who built it.
The same guidelines recommend randomized test and control groups "when feasible," with the control chosen by the same targeting logic as the test. If a network can't run a holdout, ask for a matched-market read and the method behind it. If the answer is a dashboard with no control group, treat the ROAS as a ceiling, not a result.
3. Ask how much of the number is modeled.
Some attributed sales are observed, and some are extrapolated. The guidelines call for disclosing the share that is extrapolated. You want that percentage on every report.
4. Split new-to-brand from repeat buyers.
Media that mostly reaches your existing buyers will look efficient and grow nothing. Set a new-to-brand target with finance and read it separately from total ROAS.
What to do this quarter
- Write one measurement standard (window, holdout, new-to-brand definition) and send it to every network you buy.
- Run one incrementality test on your largest network before renewing the annual commitment.
- Report incremental ROAS next to platform ROAS in every business review, so the gap becomes visible.
Closed-loop shows you the receipt. Incrementality tells you whether the ad wrote it.
Sources: IAB/MRC Retail Media Measurement Guidelines (Jan 2024) · IAB