Low-quality AI content is muddying discovery for advertisers, and buyers are naming it a top-tier concern for the first time. IAB’s newest ad spend outlook finds “AI slop” now ranks alongside AI-driven search as the industry’s two biggest 2026 investment challenges.
IAB’s newest ad spend outlook surveyed more than 200 brand and agency ad investment decision-makers between July 17 and July 31 and found buyers restructuring their playbooks around AI-driven search, agentic buying, and a growing tide of low-quality AI content.
Eighty-six percent of buyers are already making changes, or plan to in the next six to 12 months, to how they measure performance for an AI-driven web. Measuring brand visibility and citations inside AI tools leads those changes at 48%, followed by using branded search or direct traffic as proxies at 44% and turning to third-party AI-driven discovery analysis tools at 40%.
The urgency traces back to buyers’ top challenge list. Adapting to evolving consumer behavior, including AI-driven search, ties for first place at 44%, matched for the first time by concern over “AI slop,” or low-quality AI-generated content, which debuted on the list at 38%. IAB notes that concern is driven largely by small and mid-sized advertisers, who likely have fewer resources to address it.
Understanding agentic AI ad buying and execution remains a top-five challenge at 34%, though that is down from 40% in January, and comparing AI-driven customer journeys against traditional ones is buyers’ single biggest measurement headache at 45%, ahead of getting consistent AI visibility and citation data at 35%.
Buyer focus areas tell a similar story. Optimizing content for AI-generated answers is now the top priority at 76%, edging out AI LLM models at 72% and overtaking generative AI use in media campaigns, which slipped to 69% from 78% in January. IAB reads the shift as buyers moving past experimentation and into strategy for navigating AI’s broader impact on discovery.
Agentic AI ad buying and campaign execution cooled the most among focus areas, falling to 54% from 66%, which IAB attributes to January’s peak in attention easing as buyers settle into the work rather than retreating from it.
