There’s an interesting article by MusicAlly on The Register, which suggests that Napster subscribers are sharing their logins with their pals in order to save cash. It suggests:

Apparently it’s a relatively common practice, at least among these London youngsters, for one person to pay for the £9.95 per month Napster account and then to distribute the username and password among several others – in exchange for favours and drinks. Our contact couldn’t remember exactly how many people she’d given the details to, but stated that she knew for certain at least two other people who used her account on a regular basis.