I currently have 2 sites both of which use amember. I am hoping to do this for the sites. 1. I join site A and pay to become a premium member on it. 2. I go to site B and while creating a account i have a special payment option i select that is (im a member of site A). 3. I create my account and then the payment page sent me to a page on site B still. 4. That page asks me to put in my user name and password for site A. 5. If they are correct it gives me premium membership to site B as well. 6. When my subscription runs out on site A it will expire my subscription on site B simultaneous. Both sites are on the same server so the database reading problem will be easily.
Hmm... this is one for Alex and aMember techs to answer, as it's a bit beyond the scope of what we could tell you right off the bat...