This is a plugin for Wordpress which makes it into a membership system. The makers have done a very good job at creating a simple to use product for turning a wordpress site into a membership site. It has some advanced features like increasing the level of membership over time. However its not clear if when the person cancels this sequence is stopped.

It seems like a good program, and has some very strong marketing behind it. Initial inspection shows it as a good system for a basic wordpress membership system if you want to use paypal and a couple of other payment systems. However, it doesn'tprotect the content from hotlining or have an affiliate system built in.