To grow client bases profitably, this marketing tactic is used in a number of sectors, such as gaming, finance, and e-commerce. Refer & Earn application𝐬𝐚𝐭𝐭𝐚 𝐤𝐢𝐧𝐠s use word-of-mouth advertising by motivating current users to tell others about the app. Typically, these apps use tracking systems to distribute rewards and attribute referrals accurately. The incentives that are given can be anything from free merchandise and special privileges to cash and discounts.