Retail & commerce · also called Closed-loop attribution
Closed-loop measurement
Closed-loop measurement links ad exposure directly to actual sales data for the same people, typically within a retailer or data owner, showing whether ads led to purchases.
Most advertising measurement has a gap: the ad platform knows who saw the ad, but not who bought in store. Closed-loop measurement closes that loop. A retailer knows both who was exposed to an ad on its site, app or partner channels, and who bought what, online and, via loyalty cards, in stores.
That enables reports such as sales attributed to a campaign, ROAS and new-to-brand customers. It is the main selling point of retail media and commerce media. Off-site campaigns can be closed-loop too, matching exposure logs with purchase data in a data clean room.
The caveats: "attributed" sales are not necessarily incremental, because people who were going to buy anyway also see ads, so incrementality tests with holdout groups matter. Each retailer's methodology, attribution windows and view-through rules differ. And the retailer is measuring its own ads, so independent validation and standards, such as the IAB and MRC retail media guidelines, help build trust.
Think of it like this
Closed-loop measurement is like a shop that can see both who picked up a flyer at the door and who then bought the product at the checkout.
An example
A snack brand runs off-site video ads through a US retailer. The retailer's clean room shows exposed loyalty members bought 12% more of the brand in the next four weeks than similar unexposed members.
Related terms
Retail media
Retail media is advertising sold by retailers, on their own websites, apps and stores or elsewhere using their shopper data, letting brands reach customers close to the point of purchase.
Attribution
Attribution is the process of assigning credit for a conversion, such as a sale, sign-up or install, to the ads, channels or touchpoints that a customer encountered beforehand.
Incrementality
Incrementality is the extra result, such as sales, installs or visits, caused by advertising that would not have happened without it, usually measured by comparing exposed and unexposed groups.
Data clean room
A data clean room is a secure environment where companies combine and analyse their customer data together, getting aggregated insights or audiences without exposing each other's raw personal data.
ROAS (return on ad spend)
ROAS (return on ad spend) is the revenue generated by advertising divided by the money spent on that advertising, usually shown as a ratio like 4:1 or 400%.
Sources: IAB: retail media, IAB Tech Lab Open Private Join & Activation (clean rooms)