I can tell you on average per minute they use. When I brought up
VideoSlacker.com, I talked to the sales guys at Server Beach. One of the selling points was that they host YouTube. Then, the salesman told me how much they use per minute in transfer. I wanted to faint! When I signed up, I told him to make fucking sure that I was no where near their subnet. He told me that they're on a subnet on their own on a private lan. If you want to know how much they use, call up ServerBeach.com and they will use it as a sales pitch. Go to
http://www.serverbeach.com and look under their customer section on the frontpage.