There is one sure way to finally get rid of cyberspace sites that keep pestering you to sign up on them: do the initial steps of signing up without giving any of your personal passwords, and then inform them by e-mail that you need to unsubscribe because you don't have a credit card. They will block you, thinking that you will e-mail them back and beg them to keep you on, not knowing that they are doing you the big favor of keeping themselves out of your world forever.