Inserting ads into a video stream on the server before it reaches the player, so the ad and the content arrive as one continuous stream. SSAI is standard in Connected TV and live streaming because it defeats ad blocking and avoids buffering, and it complicates measurement, since the client never requests the ad; VAST 4 and OMID have provisions for it.
Related terms
Cite this entry:
Agency Echelon. "Server-Side Ad Insertion." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/glossary/server-side-ad-insertion/