Commerce media is expanding in terms of numbers of players, but ad spend patterns remain the same.

“Despite an influx of new entrants into the retail media landscape over the past few years, the actual shape of ad spend share hasn't meaningfully shifted,” said our analyst Sarah Marzano, during EMARKETER’S “Commerce Media Trends 2025” summit last week. “Amazon is set to continue comfortably clearing more than three-quarters of retail media ad spending through our forecast period with Walmart coming in a distant second.”

Despite familiar trends, some new factors could adjust trends within the retail media landscape.

Tariffs create new uncertainty for commerce media networks

Tariffs will have an impact on retail media spend, but even in the most extreme scenario of tariff implementation, we still expect retail media ad spend to rise this year.

“About half of Amazon's top 10,000 sellers are based in China,” Marzano said. But many of these sellers may not have any choice but to continue spending on US-based retail media networks. “If you take Amazon, Walmart away from a lot of these smaller, independent Chinese sellers, they basically lose their ability to access US consumers.”

While tariffs would create significant headwinds, retail media’s potential as a performance channel positions it to withstand economic uncertainty. Categories like grocery, with strong domestic supply chains, may prove more resilient than general merchandise retailers dependent on international suppliers.

Last-mile intermediaries gain commerce media share

Commerce intermediaries like DoorDash and Instacart are carving out a meaningful share of commerce media revenue, confirming one of EMARKETER's key predictions from last year.

• DoorDash partnered with Topsort to enable programmatic buying for retail and delivery inventory and launched post-purchase ad units.
• Instacart partnered with Uber Eats to power ad formats on Uber's platform and rolled out access to ad inventory on Caper Carts to all advertisers.

“These companies have the opportunity to act like retailers with many of the same advantages, where you have high purchase intent, high frequency audiences, very granular purchase data—but they also have unique advantages, like the ability to incorporate cross-merchant purchase behavior,” Marzano said.

The race for new ad inventory accelerates

Commerce media networks are looking for new ways to introduce ad inventory as on-site advertising spaces reach maximum capacity.

Amazon announced "Retail Media as a Service" in January, offering its retail media technology to help power ads on other retailers' websites. The company is also exploring AI-generated content as a surface for advertising, with its AI shopping assistant Rufus now featuring shoppable video ads.

“Post-purchase real estate is something that's actually kind of perked up quite a bit in the last couple of years in retail media," Marzano said, highlighting DoorDash's approach to boost basket sizes by offering post-purchase add-ons.

Financial players are also finding creative ways to overcome the challenge of limited digital audiences on their owned properties. PayPal recently announced its offsite ads product, which leverages transaction data to target customers across the open web.

Financial players, like Chase Media Solutions, can also offer new perspectives on consumer behavior across transactions. “We have a holistic view on who that consumer is, beyond just the retailer,” said Lauren Griewski, head of sales and partnerships at Chase Media Solutions.

Watch the full session.

This was originally featured in the Retail Media Weekly newsletter. For more marketing insights, statistics, and trends, subscribe here.