This is the XF 2 version of Referral Contest.
If you are looking for a simpler referral system, check out my Referral System add-on.
Referral Contests allows you not only to create referral contests for your members, but you can also make your board invitation only.
Referral contests are...
Create referral contests (NOT mandatory for referral links to work)
Make your board invitation only (Optional)
Create and manage contests
Create and manage referral tools: banners, text links
View who referred who
View who invited who
[TH] Invitation - A ThemeHouse add-on, enhancing your community experience.
This add-on allows your users to invite new users to your forum.
Invite new users to your board
Increase participation by current users
Option to require invitation for registration...
XC Invitation & Paid Registration System is a fully-featured add-on allowing to enable free/paid invitations/referral and paid registration on your community. Product provides a solid system of monetizing the community using invitations and paid registration packages, as well as anti-spam...