I've just run a test transaction using ClickBank, s2Member Pro v110731, in combination with WP Multisite and Buddypress. Result: Partial Fail.
DESCRIPTION
The ClickBank page shows the proper text required by ClickBank, and the Click Here To Register link on the Thank You page works, but with my configuration (WP MultiSite and BuddyPress) the registration remains incomplete.
Once ClickBank has approved the transaction, the user is directed to the registration page and may complete the required information to create an account. Once the user has entered their information and presses the button to continue, the page refreshes and they are brought back to the Membership Options page and must log in.
The user may log in, but has no access to any s2Member restricted material because they are only registered on the Network Site and not the Admin Site.
In order for the newly created user to access s2Member restricted material, the user must be registered on the Admin Site.
SOLUTION NEEDED TO FIX
Newly registered user through ClickBank on Network site must be automatically added to Admin Site.
CURRENT STATUS
s2Member Pro does not automatically add newly registered users to Site Admin area, preventing those users from access to s2Member restricted content.