I am not going to say that was a dumb question but look for yourself: http://www.alexa.com/site/ds/top_sites?ts_mode=global&lang=none
I don't know! Ask Hillary Clinton.. she used it for part of her early campaign to do public polls and such! Boulder
YouTube is now more popular than Google now. It is ranked 2 after Yahoo and Google dropped down into Rank 4. At least Google owns YouTube or have bought it. Good for them.
i am always amazed how a service, which serves so crappy videos, in terms of quality, can be so popular.