IME, youtube ads seem to come on dynamically, with dynamic amount of "forcible viewing" time, eg 5sec, 30sec, 60sec, etc. It does a pretty damn good job of show

IME, youtube ads seem to come on dynamically, with dynamic amount of "forcible viewing" time, eg 5sec, 30sec, 60sec, etc. It does a pretty damn good job of showing me the most ad without my walking away in disgust. For example, I was on a binge of science videos and the ads went from 0 sec, to 15, to 30, in lock-step with my curiosity.