The story. Retail media measurement works by tracing a shopper’s exposure to an ad back to a transaction — attribution — but that’s no longer the bar buyers are holding the channel to. As retail media pushes upstream from lower-funnel performance into brand and awareness budgets, the question boards are asking has changed to incrementality: did the ad cause a sale that wouldn’t have happened anyway. Katie Daleo, GM of CPG Ads at DoorDash Ads, made the case at Ascendant Network’s inaugural Retail + Commerce Media Upfront (SHOWCASE) this month. (AdExchanger, “A Bigger Role For Retail Media Comes With A Higher Bar For Measurement,” 17 September 2026)
01What happened
- Attribution and incrementality aren’t the same question. Attribution ties an impression to a transaction; incrementality asks whether that transaction would have happened without the ad — the harder, board-level version of “did this work.”
- DoorDash’s own numbers make the incrementality case. Two-thirds of DoorDash users are undecided about a purchase when they open the app, and in one beverage-brand campaign, 56% of the buyers reached through DoorDash advertising were net-new customers the brand hadn’t already acquired in-store — figures DoorDash and research partner Circana are using to argue the channel earns credit beyond last-touch attribution. (Vendor-supplied figures; DoorDash is the platform making the case for its own channel.)
- Certification is entering the conversation. The Alliance for Audited Media was named as a body that could independently certify retail media measurement methodologies — the kind of third-party validation attribution-only models never needed because the claim was narrower.
- The venue matters as much as the claim. SHOWCASE, Ascendant Network’s first dedicated Retail + Commerce Media Upfront, is itself a signal that retail media is being pitched to buyers as an upfront-grade category, not just a bolt-on to search and social budgets.
02What it means inside a GAM network
Retail media’s measurement infrastructure is becoming table-stakes as the channel moves upstream into awareness — operators need to understand how first-party transaction data maps to programmatic attribution inside retail DSPs.
For a GAM operator, the shift matters less as a buy-side measurement debate and more as a data-plumbing question: retail media’s whole pitch rests on first-party transaction data that a publisher’s own ad server never sees, which is exactly why retail DSPs run their own closed measurement loop instead of plugging into the open auction’s usual signal chain. As incrementality claims move that channel toward brand budgets, publishers running commerce or loyalty inventory should expect retail media buyers to demand the same rigor from any programmatic path into that data — which raises the bar for how cleanly a publisher’s own first-party signals map into a retail DSP’s attribution model, not just whether the integration exists.
Retail media grew on attribution because attribution was enough to prove a performance channel worked.
03What publishers should do about it
04The bottom line
Retail media grew on attribution because attribution was enough to prove a performance channel worked. Moving into brand budgets means proving something harder — that the ad caused a sale that wouldn’t have happened otherwise — and DoorDash’s SHOWCASE pitch is an early, vendor-funded version of that argument, with the Alliance for Audited Media floated as the independent check the category still lacks. For a GAM operator, the real exposure isn’t the measurement debate itself; it’s whether your own first-party data plumbing can hold up once retail media buyers start asking for the same rigor on your inventory.