“In our analytics-obsessed world, it’s tempting to first ask how to measure whether something is a view, but if we take a step back and just ask what a “view” is, the answer becomes clearer. What is a view? It’s when someone watches the video. And Facebook counts views significantly before people could be said to be watching the video.”
This is a very common situation: something that looks like a simple binary turns out to depend on setting a threshold on some continuous variable. At extreme values the choice is obvious, but the hard work lies in the ambiguous zone in the middle. Active users, time spent, retained users, …
https://medium.com/@hankgreen/theft-lies-and-facebook-video-656b0ffed369