Hook rate is typically calculated as 3-second video plays divided by impressions. It isn't a standard platform metric, but performance advertisers use it widely because the first seconds decide whether anyone sees the rest of the ad. A low hook rate means the opening isn't earning attention, no matter how strong the message that follows.
It's often paired with hold rate — the share of viewers who keep watching to a later point, such as ThruPlays or 15 seconds — to separate a strong hook from a strong body. Testing new openings on an otherwise proven video is one of the most efficient ways to improve video ad performance.
Example
A video ad gets 2,800 three-second plays from 10,000 impressions — a 28% hook rate — while a new version opening with a bold on-screen question reaches 39%.
How Sloss Digital uses it
We track hook and hold rates for every video ad and iterate on openings first, since a better first three seconds lifts everything downstream.