The television media landscape is evolving as viewers shift from linear TV (traditional broadcast and cable) to connected TV (CTV), which includes streaming video watched on smart TVs or internet-connected devices.
This transition is making TV advertising more addressable, prompting a debate about what defines "television" in 2025—whether it’s the format, device, or media owner.
WARC’s Global Ad Trends: The Changing Shape of TV report analyzes a decade of ad spend data to highlight linear TV’s decline and the rapid rise of CTV. It explores why definitions of TV are fragmenting and how data, devices, and creative strategies will shape its future. Alex Brownsell, WARC Media’s Head of Content, notes that linear TV’s role is diminishing in both viewership and ad spend as audiences embrace CTV’s growing ecosystem.
New players, including Big Tech, retail media sellers, and smart TV manufacturers launching ad-funded channels, are vying for brand advertising dollars. Advertisers must now reconsider how they define TV—whether as a video ad format, a media owner, or simply the largest screen in the home—affecting planning, buying, frequency management, and measurement.
Between 2014 and 2024, linear TV ad spend declined 27.5% in absolute terms, or 50.8% when adjusted for inflation. Sector trends vary: tech and electronics ad spend on linear TV dropped 42%, while household and domestic products rose 12%.
Despite this, linear TV still accounts for over 75% of TV ad investment. However, brands are increasingly shifting budgets to CTV, which represents nearly half of U.S. TV usage, according to Nielsen.
The total video market (excluding social video and YouTube) is expected to hold a 15.9% share of ad spend in 2025. CTV ad spend is projected to reach $39.9 billion (3.4% of total ad share) in 2025, growing 3.6% to $44.7 billion in 2026.
Nielsen’s 2025 Annual Marketer report shows 56% of marketers plan to increase OTT/CTV budgets, up from 53% in 2024, with stronger growth in the Americas compared to APAC and Europe.
A generational gap emerges in the shift to TV streaming
In the UK, linear TV’s weekly reach has fallen by 10 percentage points since 2021, per Ofcom, standing at 73.8%. In the US, older audiences still watch over two hours daily, versus 81 minutes for 16–24s, according to GWI data.