I would also highly appreciate additional membership status with specific restrictions ie.
free = no registration, slowest speed (50kB), captcha
registered = registered (verified email), slow speed 250kB, no captcha
premium = paid account, unlimited speed, no captcha
This is really important because if you are unable to transform unregistered users to registered (there is no befit for them to register) you won't ever get any contact at those people to give them special offer.