mediaROI opens Spain and appoints Cécile Baux Head of Sales Spain

Paris and Madrid, September 22, 2026. mediaROI, the first European AI-Native platform dedicated to Marketing Mix Modeling, calibrated attribution, and incrementality, announces the opening of Spain, its first market outside France, and the appointment of Cécile Baux as Head of Sales Spain. She joined the company on September 1, 2026.

Trilingual (French, Spanish, English), Cécile Baux brings more than fifteen years of experience in AdTech, programmatic advertising, and media effectiveness measurement. At RTB House (2019-2025), she built the Spanish business from scratch, launching more than 70 brands and running long sales cycles with marketing departments and major media agencies. Previously, at Mitula Group, which became LIFULL Connect (2011-2019), she led commercial expansion across Southern Europe and Latin America.

In Spain, Cécile Baux will drive mediaROI's revenue strategy across the full scope: business development with advertisers and agencies, management of existing clients, and evangelism of mediaROI's measurement approach (MMM, attribution, and incrementality) with the market and its leading events.

Adevinta Spain already measures its media effectiveness with mediaROI on its coches.net and Milanuncios portals, as does Student Experience on the Spanish market. With Cécile Baux, mediaROI has a dedicated commercial presence in the country for the first time.

"I am delighted to welcome Cécile to the team. Her arrival marks an important milestone for us: Spain is the first market we are opening outside France, and the beginning of our European expansion," says Antoine Szalewski, CEO and co-founder of mediaROI.