Onsite media

Onsite media is advertising that a retailer or other commerce company sells on its own websites and apps, such as sponsored products, sponsored brands and display ads, targeted and measured with its own first-party data.

Onsite is where retail media began. The IAB defines on-site commerce media as placements on the network's own digital properties that use its first-party behaviour and transaction data and are built into the shopping journey. It lists four common formats: sponsored products, sponsored brands, display ads and sponsored brand video (IAB, July 2025).

Onsite media has two strengths. Shoppers are already in buying mode, so ads sit close to the purchase. And the retailer sees the whole path from impression to order, so attribution is closed-loop. Its limit is supply. Onsite inventory is capped by the retailer's own traffic, and by how many ads it can show before the shopping experience suffers. That cap is why networks extend into offsite and in-store media.

Spelling varies. IAB documents write "on-site", while many networks write "onsite"; both mean the same thing.

Example: A shopper searches "oat milk" in a grocer's app. The first two results are sponsored listings bought on a cost-per-click basis, and a banner for a new brand sits above the category grid. The grocer then reports which exposed shoppers bought the product within its attribution window.

Related terms: sponsored products, offsite media, in-store media, retail media network, CPC.

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

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