There are rewards for both the referrer and the referred user in DoorDash's user-friendly referral program. Referring new cardholders earns rewards with the Amazon Prime Rebit starz slotswards Visa Signature Card in the online retail space. In addition to extra benefits for Amazon Prime subscribers, this card offers cash back on purchases. The Robinhood app gives away free stocks to investors in exchange for referring new users. Customers can earn stocks from well-known companies through Robinhood's simple referral program.