Refer Back and Earn is an option where you can earn via Indirect Referral System.
Indirect Referral is available for Affiliate Networks. For up to 5 levels you can earn by the Referral back system. That can give you a profit of 15%.
As someone joins SOS Profit Inc. from your referral link that would be your direct referral and after that if a new user joins via your referral�s referral link then you will get a commission as per company policies.