As a freelancer, I have been added to many FC stores- since that's nicer than asking for their user/pass.
Over time the stores my account is part of has grown. It would be nice to either:
1. be able to remove myself when I am not the 'primary' user
2. create time-limited accounts (ie - 30 day user for this account, unlimited)
would be much easier for me. I could see #2
as a selling point maybe?