Might also have something to do with "user management" of the device in question. Me, sending and receiving a bunch of E-mails on my BB for work probably is not going to use near as much bandwith as the little high school girl spending all day browsing her friend's MySpace pages and doing web searches for the latest breaking news about Leonardo DiCaprio's love life while downloading the latest artist Apple is pimping on iTunes. Too bad the network doesn't have enough bandwidth to accomodate both of our "needs".