Horizon Media
The largest independent advertising agency in the United States, managing over $8.5bn in annual media spend for major brands.
Last refreshed: 28 June 2026 · Appears in 1 active topic
Can an independent agency outside WPP beat the holding companies at agentic buying?
Timeline for Horizon Media
Mentioned in: IAB folds agentic ad-buying into AAMP
Media's AI PivotLaunched HorizonOS Blu on Model Context Protocol on 18 June with eight named media partners
Media's AI Pivot: Horizon ships its own buying layerWhat is HorizonOS Blu and how does it work?
Who are Horizon Media's partners for its AI buying system?
How much media spend does Horizon Media control?
Background
Horizon Media launched HorizonOS Blu at Cannes Lions on 18 June 2026, an agentic orchestration layer built on the Model Context Protocol routing media buys across channels in real time, with eight named media partners: Disney, Fox Corporation, NBCUniversal, TikTok, Snap, iHeartMedia, Clear Channel, and OUTFRONT. Together with WPP's same-day announcement, the two agencies committed roughly $17bn in combined annual media spend to agentic buying on a single protocol in one day.
Horizon is the largest independent advertising agency in the United States, managing over $8.5bn in annual media spend. Founded in 1989 by Bill Koenigsberg, who remains chairman and chief executive, it operates without the holding-company structure of groups such as WPP or Publicis, giving it greater flexibility in technology adoption and media partner selection.
The Blu launch positions Horizon as the independent-agency benchmark for agentic buying outside the holding companies, with its alignment on the Model Context Protocol signalling convergence around a shared interoperability standard for agent-to-agent media trading.
Is Horizon Media part of WPP or another holding company?
