Ad spend forecasts revised up, and AI campaign types are eating the open web's share

The Interactive Advertising Bureau raised its 2026 U.S. ad-spend forecast to 12.3% growth, up from 9.5% in January, on a stronger-than-expected first half. David Cohen, IAB CEO, credited live events and tooling: "The first half was strong, major live events delivered, and advertisers have increasingly powerful tools in their arsenal to find and engage customers." The sharper number is buried in Madison & Wall's estimate: spend through automated or AI campaign types - Meta's Advantage+, Google's Performance Max - will hit 12% of U.S. ad spend (about $479 billion excluding political) this year, up from 2% in 2023, and reach 27% ($158 billion) by 2030. Luke Stillman, Madison & Wall managing director, called it "a share shift." Jellyfish VP of strategy John Dawson went further: "We don't think automation in media stops at 20% or 30% - we think it gets to 90%." Meta's Advantage+ run rate is on track for $75 billion this year, up from $60 billion, per CFO Susan Li, and Tinuiti says PMax already accounts for 60-70% of ad spend among retail clients. The channel mix tells the rest of the story: social up 16.5%, CTV up 15.6%, commerce media up 13.6%, while digital out-of-home falls 0.4% and non-CTV digital video falls 0.2%.

The crux

The fastest-growing slice of ad budgets is flowing into platform-controlled "AI campaign types" that route spend into walled gardens and are widely criticized as black boxes, while non-CTV digital video and DOOH are the only channels shrinking - the open web's yield is structurally at risk.

Sell-side read

The 2% to 12% to 27% AI-share line is the number to put in front of every publisher client: budgets are consolidating into PMax and Advantage+ black boxes, and the only defense is verifiable, curated, first-party-data inventory the automated buyers cannot ignore.

Watch

whether the IAB's flagged measurement gap - 45% of advertisers say their biggest challenge is comparing AI-driven journeys to traditional ones - produces a measurement-standard push this autumn.