Completion Rate

Completion rate is the percentage of video ad impressions that play through to 100% of the creative's duration. The numerator is firings of the VAST "complete" event; the denominator is firings of the VAST "start" event. A 15-second ad with completion rate 96% means 96 of every 100 starts ran the full 15 seconds.

Completion rate is the headline quality signal on CTV and programmatic DOOH because, unlike on the web, there's no user-controlled skip button. A low completion rate signals either a creative problem (file format incompatible, decode failures) or an inventory problem (screens being powered off mid-playout, wrapper chains timing out). 95% is the floor for premium CTV; sub-90% is treated as broken inventory.

For DOOH specifically, completion rate is more nuanced because the screen has no concept of "skip" and the inventory model assumes every started playout will complete. A reported sub-95% completion rate on a DOOH playlist usually points to a screen-side issue: power interruption, network drop, player crash. Trillboards screens report a completed impression only when the player confirms the playout reached frame N where N = duration × fps minus tolerance.

Completion rate × viewability = the buyer's effective fill rate against high-quality impressions.