To ensure fairness & prevent abuse, Refer Earn Apps often have rules and restrictions in place. A user may be limited in how many referrals they can make, for instance, or the referred user may nwin 789 apkeed to fulfill specific requirements before the referral is considered legitimate. Also, before the referral reward is given, some apps might require the referred user to complete a purchase or meet a specific activity threshold. A Simple yet Effective Model. The general idea behind Refer Earn Apps is straightforward: users who recommend others to the app get rewarded for their efforts.