Brian Gleason

Chief Executive Officer Seedtag

Last Reviewed: September 26, 2026

Executive Summary

Brian Gleason has been Chief Executive Officer of Seedtag since 1 August 2025. Seedtag is an advertising technology company founded in 2014 and headquartered in New York and Madrid, which sells contextual advertising powered by its own AI across connected TV, video and the open web. He took over from founders and co-CEOs Jorge Poyatos and Albert Nieto. He came from Criteo, where he had been Chief Revenue Officer, and later also President, Retail Media, since 2022. Before Criteo he spent more than eight years at WPP’s media investment group GroupM. There he ran Xaxis, led the [m]PLATFORM advertising technology unit as global CEO and finished as Global Chief Commercial Officer.

Career Highlights

• Chief Executive Officer of Seedtag from 1 August 2025.
• Chief Revenue Officer of Criteo from 2022, later Chief Revenue Officer and President, Retail Media, until July 2025, leading a global commercial team of more than 1,500 people.
• Global Chief Commercial Officer of GroupM, leading a portfolio of specialty media businesses.
• Global CEO of GroupM’s [m]PLATFORM from its launch in November 2016, a unit that brought together the group’s advertising technology businesses.
• Global CEO, and before that U.S. CEO, of Xaxis, GroupM’s programmatic audience platform.
• Group Chief Revenue Officer for IDG TechNetwork and IDG Consumer & SMB.

Professional Journey

Gleason came into advertising technology from digital publishing. He was Group Chief Revenue Officer for IDG TechNetwork and IDG Consumer & SMB before joining GroupM in July 2013. There he ran Xaxis, the group’s programmatic audience platform, first as U.S. CEO and then as Global CEO. In November 2016 GroupM launched [m]PLATFORM, which combined its previous advertising technology businesses and promised clients audience measurement across all online media. Gleason, by then described as the former Xaxis chief executive, was named its global CEO. He told The Drum the platform was the result of a ten-year effort and more than $7 billion of investment going back to WPP’s 2007 acquisition of 24/7 Real Media. He later served as Global CEO of GroupM’s Performance Media Group and then as Global Chief Commercial Officer, leading a portfolio of specialty businesses.

Criteo, the commerce media company, announced in February 2022 that he would join as Chief Revenue Officer, leading a global team of more than 1,500 associates. His remit grew to cover the product, R&D and sales strategy for Criteo’s retail media business, and he became Chief Revenue Officer and President, Retail Media. On 27 June 2025 he gave Criteo notice that he would resign, effective 29 July 2025, to take a chief executive role at a private company.

That company was Seedtag, which announced his appointment on 8 July 2025, effective 1 August. Poyatos became Chief Innovation Officer and Nieto a Strategic Advisor, and both stayed on the board. Seedtag has more than 600 staff across EMEA, Latin America, North America and Asia-Pacific. It sells advertising targeted on interest, emotion and intent rather than personal tracking, which it calls neuro-contextual, through an agentic AI platform it calls Liz. On his appointment Gleason called the company’s approach “groundbreaking”. Since then Seedtag has added senior leaders, including a Chief Exchange & Supply Officer in September 2025 and a former Criteo CMO as Chief Marketing & Communications Officer in March 2026. The March 2026 announcement also reported 46% year-over-year revenue growth in North America in 2025.

Education

University of Connecticut

Bachelor of Science