Agentic media buying promises faster, more flexible advertising transactions. Walled gardens will drive early adoption, but open web publishers stand to benefit as shared standards mature. To get ready for the change, advertisers need to prepare their data, infrastructure, and governance.

Key Question: How quickly will agentic media buying grow in the US, and how will adoption differ between walled gardens and the open web?

Key Stat: Walled gardens will capture the bulk of agentic transactions, but true open agent-to-agent buying will reach more than $9 billion by 2028.