Server-Side Ad Insertion (SSAI) is a widely used method where ads are stitched directly into the video stream on the server. This approach provides several clear advantages: it ensures compatibility across platforms, provides adaptive bitrate (ABR) on the ads, removes buffering when switching between content and ads, and resists ad blockers. But traditional SSAI, particularly for Video on Demand (VOD), has some key inefficiencies.
In a typical SSAI setup, a video player retrieves a manifest file: a playlist that lists the video segments making up the full stream. These include both content and ad segments. For VOD, the manifest is generated in full before playback starts, with all ad slots already defined.
As the entire manifest is built ahead of time, ad segments are retrieved and stitched in whether or not the viewer ends up watching that part of the video.. If someone only watches 30% of the video, any ads beyond that point are never seen, yet they were still fetched from the ad server and stitched into the stream. This unnecessary ad stitching drives up cost per impression and floods demand sources with duplicate requests, reducing auction efficiency.
More critically, it results in low render rates: ads are served but not viewed. This discourages programmatic advertisers, whose winning bids fail to produce impressions. As a result, fill rates decline and revenue drops.
JWP Connatix takes a smarter approach to SSAI. With Just-in-Time (JIT) Ad Insertion, the manifest still includes ad slots, but the ad segments themselves are not retrieved from the ad server until the player reaches those points during playback. In other words, ads are only fetched when they are needed.
This delivers: