When we were a smaller company, Facebook login was widely adopted, and the growth rate for it has been quite quick. But in order to get to the next level and become more ubiquitous, it needs to be trusted even more.
I think Facebook is an online directory for colleges... If I want to get information about you, I just go to TheFacebook, type in your name, and it hopefully pulls up all the information I'd care to know about you.
When we are thinking about stuff like embeds, we are not thinking about how we are competing with YouTube. We are thinking about how are we going to make it more useful for people to share stuff on Facebook.