The irony is that if they put it at or near the end of the video, after I have learned that I like whatever I watched, I am much more likely to do so, because I often really do just forget to like things, and a reminder near the end would in fact make me go ‘yeah, this was good, I’ll do that’.

But if they ask me to do it at the beginning, I won’t do it until I have seen enough to decide I do in fact like it.