Maybe I am just confused when it comes to Facebook and the many thousands of social networks that is out there but the idea of “like” is purely that when someone watched the video, they will decide that if they actually liked it, they may click the like button which then informs everyone else that s/he liked the video and not the like button being used purely as a marketing tool for videos that people otherwise would not watch in any form even if they was given the option of watching the Twilight saga.
Now I am sure we have all seen an example of this but if not, I am going to show you an example from the place I am sure all of my fans love, Wrights Productions. In case you do not know but the fan page for Wrights Productions require that you like their page before watching a video, before actually knowing if their videos is good or not (will add the Facebook fan page forces you too, not the website so likely a default setting but still a good example of it).