With our membership module you can have some flexibility with how your members interact with your site.

You can setup "sign up packages".  Members can join for free.  Or you can charge a one time, monthly or charge every (x) days for membership.  You can also give a "free trial" period.

You can give members access to specific pages.  You can choose which members can have access to which pages.  You can give special pricing in the in the E-Commerce module based on a specific group. (For example you can have a Retail member group, and Wholesale member group.  then grant different pricing to each group)

Members can create Gift lists and Wish lists in the E-Commerce module.

Members can subscribe to blogs

You can mail your members several different kinds of notifications.  Some automated some manually generated.