In this episode of , Kevel CEO James Avery talks with Dr. Mark Grether about building PayPal’s global commerce media business — and what the rise of AI means for the future of shopping.
Commerce media is seeing retailers and platforms racing to grow their ad revenue while protecting the customer relationship.
In this episode of Unlocking Retail Media, Avery, sat down with Dr. Mark Grether — VP & GM of PayPal Ads — who is leading PayPal’s effort to build a global advertising business from the ground up. It’s an advertising platform powered by PayPal’s “transaction graph,” which captures the behavior of more than 400 million consumers and 30 million merchants worldwide. Here are the five biggest takeaways from this expert conversation.
“Facebook has the social graph. TikTok has the interest graph. We have the transaction graph.”
- Dr. Mark Grether
PayPal sits across 30 million merchants, giving it visibility into how and where people buy across the entire web. While most retailers only see their own traffic, PayPal’s data provides a horizontal, cross-merchant view of commerce.
“Even the largest retailers only know what’s happening on their own sites,” Grether pointed out. “We can see who’s buying where, when, and at what price points.”
This broad visibility allows PayPal to deliver market-wide measurement and optimization that no single retailer can match — helping brands understand total market behavior, not just performance inside one channel.
“In the very near future, consumers will make purchases on Google, ChatGPT, or Perplexity,” Grether explained. “That means fewer and fewer people will go to merchants’ websites.”
With merchants at risk of losing both traffic and shopper relationships, PayPal built a response: Storefront Ads.
“We’re taking a merchant’s storefront, putting it into an ad, and running that ad on any publisher website. The consumer can complete the transaction inside the ad itself — powered by PayPal.” he shared.
This is a major shift for commerce media. Any publisher surface can now function as a point of sale. Consumers enjoy seamless checkout, publishers retain traffic, and merchants preserve direct customer relationships — even as AI platforms intermediate more of the shopping journey.
Today’s brands want proof of both incrementality and market share growth.
“Everyone talks about incrementality, but the first question from the CFO is, ‘How is my market share changing?’” Grether said. “Once that’s decided, the CMO asks, ‘Where should I spend to drive incrementality?’”
Because PayPal sits across many merchants, it can reveal both market-share growth and incremental sales lift within a single system. This gives brands a unified measurement framework:
“We can show how your brand is performing across merchants — how much spend increases your share, and which channels deliver new orders or larger baskets.”
- Dr. Mark Grether
Many retail media networks experience an initial surge — 12 to 18 months of growth — before hitting a plateau. According to Grether, this slowdown often happens because retailers launch quickly without assessing whether they have the core ingredients required to scale, especially offsite where “the margins are much lower” and purchase intent weakens.
Grether highlighted five questions every retailer should ask before investing heavily:
Grether also reminded listeners, “We don’t need 300 or 400 retail media networks. Consolidation is coming.” For many retailers, partnering or joining larger networks may be more viable than going it alone. Pressure-test your differentiation early, and scale only when the foundation is truly strong.
One of the biggest strategic errors a retailer can make? Separating data from media.
As Grether put it plainly, “If you really want to monetize your audience data, you need to combine it with media. That’s the only way to get the value you deserve.”
Selling raw data through marketplaces may offer short-term revenue, but it erodes long-term advantage. The moment audience data can be activated elsewhere, advertisers have little reason to buy your owned media.
Grether was clear on the long-term risk: “In the moment you give it away, there’s no need for brands to buy your first-party media. In the long run, you’re killing your own business.”
The leaders — Amazon, Meta, Google, and PayPal — never sell their audience data. They activate it within controlled media ecosystems. Retailers should do the same to maintain control, uphold consumer trust, and protect pricing power.
PayPal’s strategy signals where commerce media is headed — toward cross-retailer analytics, AI-native shopping experiences, and measurement systems that connect spend to both incrementality and market share. The landscape is becoming more competitive, more consolidated, and increasingly shaped by AI-driven discovery.
For retailers, the roadmap is increasingly clear: prove your data’s uniqueness, build with scale in mind, prepare for offsite AI-driven purchasing, and never separate your data from your media. The networks that protect their assets — and evolve how they reach customers — will be the ones that thrive.
For more insights like these, tune in to the full episode of Unlocking Retail Media, the podcast where Kevel CEO James Avery sits down with industry leaders and innovators shaping the future of retail advertising.
Listen to this episode with Dr. Mark Grether here.
