Three-fourths of U.S. consumers are expanding their media sources with streaming subscriptions and TV-connected devices.
The growth of the content that people watch results from a wide choice of modern devices. More people are ditching traditional TV and switching to streaming services like Netflix, Hulu, and YouTube TV. This shift has made OTT (Over-the-Top) advertising one of the fastest-growing trends in digital marketing.
OTT ads appear on streaming platforms, reaching viewers on smart TVs, smartphones, and other internet-connected devices. Unlike regular TV commercials, they allow advertisers to target specific audiences and track results more accurately.
Why is OTT advertising popular? This market is growing fast, with user participation reaching 52.8% in 2025 and 61.0% by 2029.
It can be a good reason to expand your digital marketing plan and start OTT advertising. If you need to figure out the OTT advertising meaning and how it helps enhance business strategies.
OTT Advertising Guide To Expand Your Digital Monetization
What is OTT Advertising?
OTT advertising is targeted advertising content delivered on OTT platforms and Connected TV assets through streaming media by utilizing programmatic technology. Let’s briefly see the meaning of these terms. They are slightly different. And many marketers used to substitute them.
- OTT is a streaming media service provided by Netflix, Hulu, Tube, Crackle, Xumo, Apple TV Plus, Disney+, and other OTT platforms.
- Connected TV means any devices that connect to the internet and facilitate the streaming of OTT content on a television screen. This category includes smart TVs (e.g., Apple TV, Roku) and gaming consoles such as Xbox and PlayStation.
As we see, Connected TV and OTT are not synonymous. Connected TV is the device, while OTT, on the other hand, is the method of content delivery.
Why is OTT advertising popular now?
Ad spending in the OTT Video Advertising market worldwide is projected to reach US$207.52bn in 2025. According to the global marketing platform, OTT/ CTV apps, and supply-side platforms that serve for the programmatic advertising in OTT/ CTV, sharply raised over the last year.
Digital video ad spending on OTT services like Hulu and OTT/ CTV platforms like Roku are growing in the United States every year. One explanation for the rapid growth is the popularity of the video content and OTT viewership particularly. For example, in February 2025, streaming reached a record 43.5% of total TV viewing in the US, while traditional TV fell to 44.4%.
More and more pay-TV subscribers now prefer watching the video content via streaming services. Thus, marketers do not miss an opportunity to run ads on traditional TV and streaming platforms.
Given the above, OTT ad revenue tends to increase. According to the report, nearly everyone who is online worldwide is a digital video viewer. Some 2.50 billion of those viewers will be watching YouTube in 2025, and 2.25 billion will be watching subscription OTT (sub-OTT) videos.
More and more people are watching shows and movies through streaming platforms instead of traditional TV. As a result, advertisers are shifting their budgets to reach audiences on these platforms. In Q4 2024, Disney+ and Hulu reported a 16% increase in advertising revenue, showing that their ad-supported models are working well. NBCUniversal also shared strong results from its streaming service Peacock, which combines premium content with ads.
OTT platforms invest in advanced tools to stay competitive. At the beginning of 2025, Roku has launched Roku Data Cloud, an expanded version of its previous data exchange platform. The platform improves access to its own TV data for advertisers and partners. Roku emphasizes that it remains focused on media services, not on selling data directly. Among platform partners, there are Omnicom Media Group, PMG, Innovid, iSpot, and Yahoo DSP.
Benefits of Over-the-Top Advertising
Over-The-Top video advertising becomes trendy due to the benefits it brings to all participants of the ecosystem. It is free from the strict pre-planned schedules and geographic boundaries that traditional TV offers. The viewers like unlimited content as well as a flexible way of watching on various devices. Advertisers and marketers like that OTT advertising offers expanded capabilities. They can use OTT video ads to move the customers through the whole marketing funnel and track marketing performance. Let’s list the main benefits.
1. Granular Targeting
In contrast to traditional TV that does not have targeting capacities, OTT advertising allows to use the audience detailed data and demographic characteristics. Marketers can design a more relevant and personalized ad, and move the customers through the marketing funnel to buy their products.
2. Retargeting Across Channels
Due to the various metrics such as website retargeting, IP targeting, and device thumbprints, marketers can realize cross-channel advertising. They can know exactly the history of the purchases and build the next marketing campaigns even more effectively.
3. Tracking Capabilities
OTT enables tracking the ad views, web and mobile downloads, and sales. Advanced data also allows following the performance of the marketing campaign, and building the next ad optimization based on the insights.
4. Dynamic Ad Insertion
It is a server-side video ad technology that enables serving the video ads into linear programming and video-on-demand content, and taking advantage of programmatic monetization across all devices with Ad Exchange for Video.
How OTT Advertising Works?
- How to Buy OTT ads
Guaranteed Insertion Order is an old-fashioned type of direct deal between advertiser, agency, and publisher that contains the details of the ad placement. The setting is done manually.
Data-Driven Programmatic buys are based on real-time bidding that allows advertiser and agency targeting but does not guarantee set impressions or frequency.
- OTT Ad Insertion Methods (CSAI, SSAI or “Stitching”)
CSAI, or client-side ad insertion, is also an out-of-date method in which the advertiser inserts the ad into the platform before the video starts playing. This approach has some flaws. CSAI is not adaptable to live broadcasts, which is essential for news and sports programming.
In contrast, SSAI (server-side ad-insertion method) enables the ad display without interruption due to the stitching of the ad and video content. It allows carrying live programming and showing the ads without interruptions, and even makes ads to be clickable. SSAI OTT advertising eliminates such problems as ad fraud, ad blockers, and latency.
- Tags for OTT Devices
Here we will define the tags used for communicating with OTT devices.
The Video Ad Serving Template (VAST), developed by the IAB, remains the standard for serving video ads across compliant video players. It defines how ad creatives should be delivered and tracked. However, VAST on its own does not support interactivity.
Previously, interactivity was handled through VPAID (Video Player-Ad Interface Definition), which allowed for rich, interactive ad experiences. However, VPAID did not support server-side ad stitching—a critical capability for OTT environments, especially for pre-roll ads in Europe. Due to these limitations and security concerns, VPAID was officially deprecated in 2019.
As of 2025, VAST 4.2 continues without VPAID. Instead, interactivity and measurement are now handled by two modern standards:
- OMID (Open Measurement Interface Definition): Used for standardized viewability and verification.
- SIMID (Secure Interactive Media Interface Definition): Enables secure, interactive ad experiences without compromising performance or compatibility in server-side stitched environments.
Together, VAST, OMID, and SIMID support a more secure, transparent, and seamless ad experience across OTT platforms.
OTT Header Bidding
OTT Header Bidding is an advertising technology that allows selling the OTT ad inventory simultaneously to multiple demand partners. The major point is that the unified auction happens before making calls to the ad server, which means less latency. The OTT Header Bidding technology works with the JavaScript-based VPAID container. The bidding starts while the video is loading.
Because of the large number of demand partners, media owners used to need a single solution to manage the video content monetization and to gain more programmatic revenue. For this, a header bidding wrapper, which represents a special piece of code, organizes buyers and sets rules for the programmatic auction. Moreover, the wrapper allows managing the omnichannel inventory and gaining buying efficiency across different platforms.
How To Start OTT Monetization With Header Bidding
At Adtelligent, we designed an OTT advertising platform with a single wrapper solution for selling over-the-top content to the buyers and receiving the highest bids at the unified auction. Such an approach increases eCPM by 50% and provides granular analytical data and insights to make further ad optimization better.
Adtelligent Header Bidding Wrapper for OTT/ CTV represents a holistic server-side infrastructure that helps optimize all the processes and reach the premium audiences.
Header Bidding for OTT/ CTV is gaining momentum. It allows publishers and advertisers to get the most of the programmatic advertising. The technology is a trend in the digital marketing world, and it helps enhance business strategies.