YouTube vs. Vimeo Embed
Which do you think you would be more likely to watch? Why can’t we get a thumbnail preview for Vimeo?
Update - Reply from Marco:
API requests just for that aren’t worth the latency. We need to generate the thumbnail URL having only the video ID, and Vimeo had no way to do that when we first coded this. Supposedly that has changed recently — we’ll look into it again soon