The Affiliates manager plugin can be integrated with the OptimizeMember plugin so you can reward affiliates for sending members.
Step 1 (Install the Integration Addon Plugin)
Install the OptimizeMember Integration addon.
Step 2 (Keep the Main Plugins Active)
Simply keep the Affiliates Manager and the OptimizeMember plugins active on your WordPress site.
The affiliate plugin will track all the referrals and give commission accordingly if a referred user pays for a membership.