Offsite media

Offsite media is advertising that a retailer or other commerce company sells on other companies' sites, apps, connected TV and social platforms, targeted with its own customer data and measured against its own sales.

The IAB defines off-site commerce media as placements outside the network's owned platforms that still use the network's first-party audience data for targeting and optimisation. It lists display, in-app, connected TV, digital video, audio, digital out-of-home and in-game ads as common formats (IAB, July 2025).

Offsite media answers onsite's supply limit. A retailer with 20 million loyalty members can reach them wherever they browse or watch, not only when they open its app. The data flow is the hard part. The retailer must match its customer records to identifiers that DSPs or publishers recognise, usually through a clean room, a hashed-email identity framework or a DSP partnership, without handing over raw customer data.

Measurement is closed-loop but less direct than onsite. The network knows who was exposed only through the match, so reported sales depend on match rates and attribution rules. Buyers ask for incrementality tests before they scale offsite spend.

Example: Marketing Dive reported on 1 June 2026 that Walmart Connect would let advertisers use its customer data through Yahoo DSP and the SSP Magnite, outside the Walmart DSP (Marketing Dive, 1 June 2026). The move, still a closed proof of concept, followed the end of Walmart's four-year exclusive deal with The Trade Desk in autumn 2025.

Related terms: onsite media, in-store media, clean room, DSP, commerce media.

Authoritative source: IAB, "Defining Commerce Media and Its Ecosystem" (July 2025).

Read the full guide: Onsite vs offsite vs in-store retail media.