What is server-side ad insertion, and why is it so important? 

Server-side ad insertion (SSAI) is taking the OTT industry by storm – and for good reason. If you are a broadcaster, here are some basic facts you need to know.


What is server-side ad insertion?

To explain server-side ad insertion, which is also known as dynamic ad insertion (DAI), it’s best to compare it with two other forms of ad insertion: traditional TV ad insertion and client-side ad insertion (CSAI).

In traditional TV ad insertion, all viewers are served the same commercial. It’s the farthest thing from personalized ad management. In fact, it’s the exact opposite. But online video content streaming is different, because it can offer different ads to different viewers, and even change its ads based on specific viewer behavior. Server-side ad insertion allows this personalization to take place.

Yet what makes server-side ad insertion truly special is the way that it integrates ads into the streamed content. This is where it differs from client-side ad insertion. Here’s how it works:

  1. Cue-in and cue-out markers are inserted into the original streaming manifest, in order to “mark” the ad’s designated location.


  1. The vendor communicates with an ad server, in order to receive an ad. The vendor then adapts the ad to all relevant OTT profiles and “stitches” it into the content. This is why many people in the industry refer to SSAI as ad stitching. During the automatic stitching process, a part of the content is removed, and the ad is inserted in its place.


  1. The viewer accesses the manifest via his or her device, and receives personalized content.


During the server-side ad insertion process, the SSAI vendor produces seamless content with different ads for different viewers. It’s seamless because the content and the ad are part of the same manifest. This “stitching” is accomplished on the fly, in real-time.

The server-side ad insertion method is different than client-side ad insertion, which isn’t “stitched”. In CSAI, the ad server creates a layered procedure: The original content stops, the personalized ad appears, and then the content continues.

As its name suggests, client-side ad insertion occurs on the viewer’s web browser. It is more complicated – and therefore less seamless and intuitive from the viewers’ point of view. In CSAI, the ad is more prone to be picked up by ad blockers. Server-side ad insertion, on the other hand, is stitched on a dedicated server, prior to any interaction with client features.

Why is server-side ad insertion so important?

In the end, the importance of SSAI comes down to two words: better monetization.

Server-side ad insertion works seamlessly with a variety of online content, from live streams to VOD. But when it comes to live streams, SSAI is truly revolutionary. Live streams cannot be paused, and ad stitching facilitates seamless ad integration without the need to “stop” the content stream. This is a breakthrough in live stream monetization.

Server-side ad insertion is also important because it enhances ad exchange flexibility. It allows vendors to communicate with many different marketplaces, until the ideal ad for a specific user is located.

Due to its ad-stitching attributes, SSAI also offers better ad-blocking capabilities than CSAI.

The bottom line

Server-side ad insertion is the most effective method to fully utilize the fact that online streaming allows advertisers to target specific viewers with specific ads. SSAI is the ideal method for personalized ad implementation, because it is seamless, automatic, and can make swift adjustments in real-time. Due to its capabilities, SSAI communicates great with internal or external ad campaigns, which house a variety of ads that the ad server can choose from, in accordance with viewer characteristics.