IAB: CTV ad spend to grow 14% in 2026, outpacing overall ad market
Connected TV ad spend is set to grow 14% in 2026, according to IAB, outpacing the broader ad market. AdExchanger columnist Rick Bruner writes that CTV can prove its value through randomized controlled trials, the strongest evidence of causality, run at the household, designated market area or ZIP code level. The United States has 210 DMAs, enough for large-scale national cluster randomized trials, and ZIP-level delivery could expand the number of test units further. Geo experiments let advertisers randomly assign markets to receive advertising or not, then measure changes in sales, store visits, leads or subscriptions using only ZIP code and transaction date from their own CRM, transaction systems or sales-panel partners.
Campaigns currently justified by attributed conversions rest on correlation. An exposure precedes a purchase; many of those same buyers would have converted anyway. Media plans that add CTV testing at the geo or household level can tie incremental sales directly to the P&L figures finance teams already track, giving planners a causal case for premium video budgets that search and social attribution cannot match. Bruner's push for randomized experimentation also points toward transparent, third-party-verifiable measurement standards, reducing agencies' reliance on sellers as the sole judges of their own inventory's performance.