The Programmatic Glossary
A practical glossary designed to help marketers, advertisers and ad-tech professionals understand the terminology that powers programmatic advertising
Ad Formats
In-stream video
Video ads that play within video content: before it starts (pre-roll), during it (mid-roll) or after it ends (post-roll). They appear in the same video player as the content the user came to watch.
HOW IT WORKS
In-stream ads are delivered using VAST (Video Ad Serving Template) tags, which tell the video player where to fetch the ad, how long it is and what tracking to fire. Buyers purchase in-stream inventory through DSPs (Demand-Side Platforms) via RTB (Real-Time Bidding). Key metrics are VCR (Video Completion Rate), how many people watch the ad to the end, and viewability.
EXAMPLE
A user opens a streaming platform to watch a video. A 15-second pre-roll ad plays first. The viewer can skip after five seconds. If they watch all 15 seconds, that is a completed view. The advertiser only pays for completed views, making in-stream one of the most accountable video formats.
RELATED TERMS
VAST (Video Ad Serving Template) | SSAI (Server-Side Ad Insertion) | CSAI (Client-Side Ad Insertion) | Video Completion Rate (VCR) | Connected TV (CTV)
★ LIMELIGHT INSIGHT: Limelight supports in-stream video monetisation through VAST-compatible integrations, connecting publisher video inventory to premium video demand partners.
