Audience numbers alone won’t secure CTV’s future. The real test is whether connected TV can deliver hard evidence that premium video ads actually move the bottom line.
CTV is growing fast-projected to rise 14% in 2026, outpacing the rest of the ad market. But that growth won’t mean much if the industry can’t show that premium video ads do more than collect views. The real question is whether CTV can prove that brand advertising actually causes business results, not just correlates with them.
In 2026, US CTV upfront commitments are forecast to reach $17.73 billion, surpassing linear TV upfronts for the first time-a clear sign of shifting budgets toward connected TV.
Brand advertising has a credibility problem. Its effects are broad, often influencing buyers who never click and driving sales through channels far from the original ad. Traditional attribution can show that an ad came before a purchase, but not that it caused it. Many sales would have happened anyway, so correlation can look like impact. What marketers really want to know is incrementality: which sales happened because of the ad that wouldn’t have happened otherwise?
According to IAB, CTV ad spend in the US is projected to grow by 11% to $29.3 billion in 2026, a slight slowdown from the previous year’s 12% growth. Meanwhile, the broader US digital video advertising market is expected to reach $81.9 billion, highlighting CTV’s role as a major growth driver within digital video. However, industry analysts note that despite this growth, the need for standardized measurement and attribution remains a challenge for CTV.
Geo experiments are especially effective in the US, where 210 DMAs allow for national-scale randomized trials. As targeting gets more granular, it becomes easier to detect even small effects. This flexibility-across households, DMAs, ZIP codes-gives CTV a measurement edge over search, social, and retail media.
Trying to copy digital attribution would put CTV at a disadvantage against platforms with more behavioral data and tighter closed systems. It would also reduce premium video to clicks and conversions, missing the broader business impact TV can deliver. Instead, CTV should focus on what it does best: using randomized experiments and transparent causal measurement as the standard for brand advertising.
Making experimentation routine would strengthen the case for premium video and create clear standards for how experiments are run. It would also keep sellers from being the only ones judging the value of their own inventory. With ad supply tightening and every dollar under scrutiny, being able to prove that sight, sound, and motion drive real business results is a strong position.
CTV’s future depends on shifting the conversation from audience reach to causal proof. If the industry adopts randomized experimentation as its measurement backbone, it can defend its share of ad budgets and set a new standard for premium brand advertising. Platforms that stick to attribution and closed loops will keep their place, but CTV has a chance to define its own-and finally show that premium video is more than just a nice impression.
IAB projects that US CTV ad spend will grow 11% in 2026, reaching $29.3 billion and making it one of the fastest-growing segments in advertising. The US’s 210 DMAs and growing ZIP code-level targeting make large-scale randomized trials possible, giving CTV both the reach and flexibility to credibly link brand ads to real business outcomes.
Industry reports also note that the rise of retail media and CTV is increasing the demand for measurable, performance-driven results. WPP Media reports retail media is growing over 22%, with commerce advertising expected to hit $199.6 billion in 2026. This pushes CTV to be evaluated as a performance channel, not just a branding tool (WPP Media).
Adoption of data clean rooms and advanced measurement methods is picking up, helping advertisers better prove the incremental sales impact of CTV campaigns (WPP Media). At the same time, industry observers warn that while CTV budgets are rising, fragmentation and the lack of standardized attribution are still challenges (Streaming Meme).
