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.