[whyleyc]

I think it's actually a pretty good thing to do, both for the seller and the users.

If companies didn't sell on the account details of their existing userbase these users would effectively be frozen out of any future site development/improvements (unless they re-entered all their data).

And since acquiring users is hard, from the seller's point of view an active userbase is probably one of the site's biggest assets (and also a validation that the site has some potential to it).

[DuqE]

This is what i meant that the user data is valuable otherwise you would have frozen out the existing users and have a web platform you would have to build up a userbase on again, which if this was the case then you would just start your own project as you are starting from scratch. The only upside is existing traffic to the website. Existing users who turn up one day to realise the content they have added is now gone would be a disaster for the user, then asking them to sign back up to recover that data is another unnecessary step.