User Referral and Invite module provide almost identical functionalities. We should try to implement the missing features of User Referral into Invite module and provide an upgrade path for existing users of User Referral. By doing this, we avoid confusion among new Drupal users and engage developers to join forces.
AFAIK, the missing features are:
- display a referral link (such as referral/123) in the user's page
- If the Adsense module is installed and Revenue sharing is enabled, then the referral is used to share the revenue between the referring user and the referred user.
- Detailed log: Lists each user and users she has referred, the date/time of referral, IP address and referral link.