The "like" button on youtube is a great idea. It lets you know if people like what they are seeing. However, nobody uses it! It is completely overlooked when it could be so much more efficient. My solution is similar to how links of related content appear at the end of videos, just put the "like" or "dislike" button there! They can't miss it! Also, I think it would be great if people who like a youtube video on facebook could have that like transferred to youtube. It makes so much sense.