When someone says they saw a movie, you assume they watched the whole film.
No one would claim to have seen Star Wars after watching the opening scene.
Which is why best thing I read today was the explanation in a Business Insider story about how Netflix counts viewership.
Evidently, Netflix used to tally a viewer after they watched 70% of a show. Now, you only have to watch at least two minutes to be counted.
I don’t think its going out on a limb to predict how that impacted viewership.