Watching to the end is a stronger signal
For many short-form video systems, how long you keep watching can reveal more than a like. A like is a quick, deliberate tap; finishing a clip tells the system that it held your attention for its full run. Watching it again can be an even clearer sign that the video was worth your time.
Why the algorithm pays attention
A recommendation system has to guess what you will want to watch next. It can use explicit feedback, such as likes, but it also learns from behavior: whether you stop scrolling, how much of a video you watch, and whether you return to it. Those signals help distinguish a video that earned sustained attention from one that received a reflexive tap.
That does not mean a completed view always outweighs a like. Platforms use different systems, and they combine multiple signals. But when you watch a clip all the way through—or replay it—you provide evidence that is difficult to get from a single button press: the video kept you there.
