Server-Side Ad Insertion: Bringing Significant Value to Multiscreen Advertising

Vijaya Sagar Vinnakota, Head of Ad-Tech Engineering, Amagi

Over the last few years, there has been a massive shift from traditional television to multiscreen viewing. In fact, recent research from Digital TV Research found that by 2020, 3.98 billion people will watch video content via a PC or laptop over a fixed broadband connection. As multiscreen television viewing becomes ubiquitous, broadcasters today are looking to get better value out of their content and improve upon the television viewer experience. Targeted advertising has emerged as a way to achieve those goals. By delivering targeted content to users at a personal level on second-screen devices like smartphones, tablets, and PCs, new revenue can be explored and viewer satisfaction increased. Yet, the ad insertion method that is being utilized in the majority of OTT multiscreen use cases (i.e., client-side ad insertion) has major limitations.

This article explains the challenges TV networks face when using client-side ad insertion, taking a look at how server-side ad insertion methods enable TV networks to deliver targeted, personalized content to any device, driving new revenue streams.

Client-Side vs. Server-Side Ad Insertion

The majority of multiscreen ads today are delivered via client-based ad insertion systems. Under this approach, the ad insertion technology resides inside the device’s media player. The video player requests an ad from an ad network and delivers it to the end user (See Figure 1).

Figure 1Figure 1: Client-side Ad Insertion (Source: IAB VAST 4.0 specification)

The major drawback is that once content leaves the CDN, broadcasters and advertisers lose control over the advertising playout process. Often, viewers can skip the ads, or block them altogether via ad blockers. Hence, TV networks and advertisers need a superior ad insertion technique for multi-screen television.

In comparison, by moving ad insertion to the server side (See Figure 2), broadcasters can provide a more seamless and personalized user experience.

Figure 2Figure 2: Server-side Ad Insertion (Source: IAB VAST 4.0 specification)

The following chart summarizes the benefits of server-side ad insertion vs. client-side ad insertion.

Client-side Ad Insertion Server-side Ad Insertion
Viewer experience of live streams is sub-optimal due to buffering of ads Viewer experience is seamless as ads are pre-stitched into the video stream
Viewers can skip ads through ad blockers Ad blockers will not recognize ads as they are an integral part of the video stream
Ad insertion is dependent on client application and often requires SDK integration into each client App App-independent ad insertion, making it platform agnostic
Non-linear ad format deliveries are dependent on App capability Non-linear formats like L-bands, lower thirds, overlays, etc. can be stitched into the video stream
Impossible for content owner/TV network to impose brand rules for ads if content is viewed through 3rd party OTT platforms Ad experience is controlled by TV network/content owner
Advertiser-specific rules like frequency and day cap cannot be imposed as ads are being delivered by multiple ad networks directly to the App As all ads are aggregated from different ad servers by a single server, restrictions like frequency and day cap can be imposed
Reporting is cumbersome for advertisers as they have to depend on multiple ad server reports Supports a single uniform report for the TV channel/network to advertisers spanning all ad servers

 An excellent example of the type of user experience typically encountered with client-side ad insertion is YouTube. Let’s say you are watching a video on YouTube. Each video has a progress bar with markers for when the advertisement will pop up. It’s not uncommon for the ad playout process to be delayed due to buffering or on-the-fly interaction with external ad-networks. With server-side ad insertion, there are no video markers to speak of; the content is already packaged together in a unified stream, leading to a smoother overall experience that increases user satisfaction.

In a live broadcast scenario, client-side ad insertion results in ads cutting into the content, either due to accumulated network delays while fulfilling ad-breaks or due to abrupt switches from ad-break to content (say, during live sports). A well-designed server-side ad insertion system overcomes this limitation by appropriate integration with the broadcaster, thereby ensuring the integrity of the live broadcast.

An OTT stream personalization and server-side ad stitching solution, such as Amagi’s THUNDERSTORM, has been designed for a range of live sources including SDI, RTP, RTMP, MPEG-DASH, and HLS, and supports a variety of linear video and non-linear graphics ad formats. It sits between the broadcast source and the users’ CDN, modifying the playlist manifest to enable server-side ad insertion and tracking content/ad playout metrics.

These metrics are helpful for providing tracking information to ad servers that implement IAB’s VAST 4.0 specification (or an equivalent custom server side tracking support). Ad breaks are tagged as segments of interest, and contain additional metadata such as the ad-break duration, ad-break type, and splice type. THUNDERSTORM publishes a single common playlist manifest across all users, preserving the metadata contained in the broadcast source playlist. It has the capability to consume and track external event inputs such as SCTE-35 markers and GPIO triggers to enable a seamless server-side ad-insertion in live/sports broadcasts. These live sessions can be turned into VoD and catch-up sessions as required.


OTT multiscreen service offerings are becoming a pervasive part of our everyday lives. Whether catching up on the news from a smartphone on the train commute home from work, or streaming the latest premium program on an iPad in the living room, television viewers are looking for a unified user experience across all devices.  If broadcasters want to create a more seamless viewing and advertising experience for their viewers, including personalized and targeted content, they need an ad insertion technique that is flexible, efficient, and capable of supporting monetization across all screens.

Server-side ad insertion platforms provide TV networks with an effective approach to OTT ad insertion compared with the traditional method of inserting mid-roll ads on the client-side, enabling them to bring new value to advertisements in the multiscreen environment.


About Vijaya Sagar Vinnakota

Vijaya Sagar_AmagiVijaya Sagar Vinnakota heads Ad Tech Engineering at Amagi. He has over 19 years of experience in software development covering online video technology and communications systems. Prior to joining Amagi, Vijaya Sagar was a Senior Director at Tribune Media where he led the India engineering practice for Gracenote’s data products. He also had a stint as an entrepreneur, being the co-founder and VP-Engineering at Althea Systems, a multi-screen social video discovery start-up.


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