Why the hook decides most of the result
On a vertical feed nobody chooses to watch your video. It arrives, and the viewer decides in a second or two whether to keep going. Everything after the hook, the demo, the proof, the offer, only matters to the people the hook kept. That is why the hook is the highest-leverage part of a video ad to test. Keeping the body of a video fixed and swapping only the first three seconds is one of the cheapest experiments in paid social.
