CANNES – While the industry has obsessed over online retail media for the past five years, T-Mobile has been quietly building what may be the most measurable in-store advertising network in America.
“Everybody’s been focusing on online retail media where our transactions and most transactions are happening in the store,” Cherian Thomas, head of DOOH for T-Mobile Advertising Solutions, told Beet.TV’s Andy Plesser at the Cannes Lions International Festival of Creativity. “What we’ve done is we’ve equipped over 10,000 of our stores with 35,000 plus screens.”
The key differentiator: attribution. T-Mobile can connect in-store ad impressions directly to point-of-sale data at the SKU level, answering the question every advertiser wants answered: did the register ring?
Beyond impressions to outcomes
T-Mobile’s approach represents a fundamental shift in how digital out-of-home advertising is sold and measured. Rather than trafficking in impressions, the company focuses on outcomes.
“If one of our partners is buying space in our stores, not only are we able to do a holdout group and activate 5,000 stores and hold out 500, but the best thing is we’re able to tell them, did this product sell through our registers?” Thomas said.
The results speak for themselves. “Store A that was playing your content at 14% share of voice had an increase in same store sales velocity versus the store that wasn’t playing your content,” he said. “And that’s what brands want.”
Customer-first advertising
T-Mobile maintains strict standards about what appears on its screens. “The customer is the number one stakeholder,” Thomas said. “When we talk about what ads are happening in our stores, it’s the products that we sell.”
This means campaigns from device manufacturers like Apple, Google, Samsung, and Motorola—brands whose products are already on T-Mobile’s shelves. The company traffics campaigns through its own ad server and content management system, recently enhanced through the acquisition of Vistar Media.
“Vistar also comes with best-in-class ad serving for this format and also best-in-class content management system,” Thomas said.
The rideshare revolution
T-Mobile’s advertising ambitions extend beyond retail stores. The company operates the largest network of interactive screens inside Uber and Lyft vehicles, taking the customer journey concept literally.
“You’ve got 130 million people walking around with their mobile device, and we have a great relationship with our customers to connect with them through mobile,” Thomas said. “But maybe you’re on your way to work, on your way to a stadium, on your way to a restaurant.”
A partnership with Uber for Journey TV, announced last year, adds first-party data capabilities to in-car messaging. “Our screens can say ‘Hi Andy,’ or understand that Andy is heading to Michael’s Restaurant and be able to put the right product and the right messaging in front of it,” Thomas explained.
The missing link: found
For Thomas, T-Mobile’s in-store network solves what he calls “the missing link in traditional digital out-of-home or out-of-home” — the inability to connect advertising exposure to actual sales.
“No one can really tell, ‘Did the register ring?’ Whereas within in-store retail media we’re able to say, ‘Hey, this is actually driving results,’” he said.
This capability positions T-Mobile to help other retailers as they build their own in-store networks. Speaking about a panel he participated in at Cannes, Thomas said the company is ready to share its learnings.
“If other retailers have pain points, we’ve been there and done that,” he said. “How can we actually take the learnings that we’ve done by being our own best customer and translate that into third party retailers in 2026?”
With 10,000 stores equipped and attribution solved, T-Mobile has built what many consider the holy grail of retail media: advertising at “the last three feet” with proof that it works. “We’re selling outcomes,” Thomas said, “because that’s what brands want.”
You’re watching “Dispatches from Cannes Lions 2025: Interviews on Innovation”, a Beet.TV Leadership Series at Cannes Lions 2025, presented by DirectTV, EXTE, Fandom, Future USA, Jivox, Kroger, New Tradition, Ogury, Pentaleap, Perion, Topsort, VuePlanner, and Walmart Connect. For more videos from this series, visit this page. You can find all of our coverage from Cannes Lions 2025 here.
