Mark Grether’s next build: Turning PayPal’s data into an off-site media engine

Data may be everywhere, but Mark Grether has built his career on figuring out which signals actually matter.

PayPal Ads is his latest venture. Launched in 2024, the business is built on a different premise for retail media: that transaction data — not on-site inventory — can serve as the foundation for advertising.

PayPal says it sees one-third of all global transactions, with 430 million consumers and 30 million merchants on its platform.

“When I realized that I was like, ‘Woah, that is a lot of data,’” Grether told The Current. “That’s something you can build.”

Grether, who previously helped build media businesses at Uber and WPP’s Xaxis, is betting that scale can translate into a different kind of advantage.

Its transaction graph provides advertisers with a cross-merchant view of purchasing behavior, rather than relying on a single retailer’s data or site visits. Campaigns can run off-site across any channel using PayPal’s purchase data as the signal.

“We are flipping the script,” Grether told The Current. “The scale for us is where our data is and that’s offsite.”

PayPal points to Ulta Beauty as an example of that success. The beauty brand saw a 20% increase in transaction spend and a 136% lift in brand favorability versus benchmark using PayPal Ads’ transaction graph, according to the company.

Dan Robbins, PayPal Ads’ senior director and global head of growth and strategy, said the company is positioning its media network around clearer measurement of campaign performance.

“You can see how your ads deliver attribution and incrementality on sales, transactions, basket size, shopper composition, market share and more,” Robbins told The Current. “We believe commerce media should be transparent and performant.”

Off-site media is currently about one-third the size of on-site in U.S. ad spend, but it is growing at a slightly higher rate. Marketers will pour an estimated $17 billion into off-site media in 2026, with that number jumping to $25.6 billion in 2029.

PayPal Ads has not released any revenue run rate figures yet.

“The focus on data has been so critical because it’s an arms race of unique, scalable predictive data for campaigns,” Mutinex’s U.S. president, Mike Finnerty, said.

AI-driven shopping may be the next shift in that race. OpenAI and Perplexity are both working with PayPal to power their agentic commerce businesses. Through Honey, its browser extension, PayPal can see search activity on ChatGPT and Amazon, among others. That data can feed into its ads business.

Robbins said the biggest focus is on how to reach consumers as shopping shifts toward AI-driven discovery.

 Retail media branches out

Nontraditional advertisers like PayPal, Mastercard and Chase Media Solutions have launched media networks in the past two years, giving rise to so-called financial media networks.

Spending in the segment is still relatively small — just over $1 billion compared to an estimated $71 billion in retail media networks in 2026 — but it’s growing at the highest rate of any type of media network, with projections reaching $1.8 billion next year.

“What PayPal and, increasingly, what Chase is trying to do with their media network is providing a much broader holistic view of purchase behavior,” Finnerty said. “It’s pretty smart and compelling.”

As that growth continues, Grether said 2026 will be a key year for telling the PayPal Ads story, including building a strong sales force with ‘boots on the ground.’

Turning small businesses into retail media powerhouses

Fragmentation remains one of the biggest challenges in retail media. Advertisers now work across an estimated 275 networks globally, each with its own inventory, data and buying process.

PayPal’s response is to leverage the combined power of its 30 million merchants to create scale from businesses that individually aren’t set up to sell advertising.

For advertisers, that could mean access to inventory and audiences that would otherwise be difficult to reach in a single buy. For merchants, it offers a way to monetize site traffic. For PayPal, it’s a way to create on-site inventory to complement its off-site data advantage.

“If you really want to differentiate yourself in the marketplace, you have to have proprietary data and you have to have proprietary supply,” Grether said. “The data we already have, and now with the SMB network, we are also now creating proprietary supply.”