I have video tutorials that I am selling. It is important that when someone pays for the videos and becomes a member that they can't give their username and password to other to let others login. Does "aMember" stop this?
It is impossible to prevent situation when user gives their username/password to a friend, and it is not a problem really. It is a problem when someone publish username/password in some public place and lot of visitors downloading your content for free.
And aMember has great protection against this - it will count number of IP used by each customer for configured period of time and if limit is reached, account will be immediately locked.