One thing that needs to be clearly disclosed when signing up to anything — be it software, an energy company, or a newspaper — is what they try to do when you wish to close your account. This really needs to be in plain writing and not buried away in the Terms Of Service.
I’m experiencing this now after recently switching my energy provider. Even after the account is closed, they are sending me messages about the special offers I can have, if only I switched back to them.