From what I recall of going to the cinema, most people get up and leave not when the film is over but when the credits start rolling. I used to like getting my full money’s worth and, even though I now normally watch films on DVD or online, I still have the habit of waiting because I enjoy the little extras that film makers often sneak somewhere into the credits.
However, it must be said that credit rolls can go on and on. Particularly for films with a high CGI component or for fully animated ones, the full list of people involved is huge. With online films I do sometimes resort to scrubbing through the titles at high speed to see if there is anything lurking. Watching a few more DVDs over Christmas, the other trick is to turn to an online source like IMDB, which includes a ‘crazy credits’ heading. If there is something worth waiting for aside from letting names and music wash over you, you can find out in advance – like the Stan Lee cameo right at the very end of Big Hero 6 (2014) which was this afternoon’s entertainment.