Integrate Reward Card (and other cards too) with the referral system

Integrate reward card with the referral system. This is how Dropbox became the company that we all know. Dropbox create a tiered referral program back when they started where users could refer friends and earn disk space up to 2GB max. Each referred friend was 250MB of disk space which now seem insignificant but back then it was huge. So if a card user could earn points (or stamps) either by buying in store and referring friends that could be a game changer.