Amazon and Walmart Move Ads Closer to Checkout

Amazon and Walmart are shifting their advertising strategies to put more ads in front of shoppers who are ready to buy. According to Sensor Tower, Amazon generated 56% of its retail-media impressions onsite during the first half of 2026, compared with 44% offsite.

This move is significant because advertising is becoming an increasingly important profit lever for both retailers. Onsite ads can capitalize on high-intent search behavior while using first-party purchase data that traditional digital-ad platforms cannot easily replicate.

Walmart made a similar shift, increasing its onsite share to 44%, up 27 percentage points from a year earlier. This contrasts dramatically with rivals like Best Buy and Target, which placed 93% and 92% of measured impressions offsite, respectively.

The broader retail-media market is weakening, with total impressions across the 32 U.S. networks studied by Sensor Tower falling 17% year over year to 223 billion during the first half. However, Amazon still controlled roughly 60% of those impressions despite its own 16% decline.