The Programmatic Glossary
A practical glossary designed to help marketers, advertisers and ad-tech professionals understand the terminology that powers programmatic advertising
Ad Formats
Server-Side Ad Insertion (SSAI)
A video ad delivery technology where ads are stitched directly into the video stream on a server before it reaches the viewer's device. The viewer sees a continuous video, with content and ads blended seamlessly, rather than separate ad requests loading on their device.
HOW IT WORKS
When a viewer requests video content, the SSAI (Server-Side Ad Insertion) server combines the main video with the appropriate ad content into a single stream before sending it. The viewer's device receives one continuous video file with ads already included. Because the ads are indistinguishable from the content at the network level, ad blockers cannot detect or remove them.
EXAMPLE
A streaming service uses SSAI (Server-Side Ad Insertion) for their ad-supported tier. During a TV drama, an ad break appears seamlessly. There is no buffering, no loading spinner and no chance for an ad blocker to skip the ads. The ad plays at the same quality and frame rate as the show itself.
RELATED TERMS
CSAI (Client-Side Ad Insertion) | VAST (Video Ad Serving Template) | In-Stream Video | Connected TV (CTV) | FAST Channels
★ LIMELIGHT INSIGHT: Limelight supports SSAI-based video monetisation, enabling publishers and streaming services to deliver seamless, ad-blocker-resistant advertising experiences on CTV (Connected TV) and video platforms.
