Brands have been using existing customers as a way to spread special offers on social platforms. A kind of word-of-mouth analogue for Facebook’s sponsored stories except that the consumer gets rewarded rather than the platform owner. JWT Intelligence gave the following example of a micro affiliate campaign
American Express recently started offering a credit to customers who tweet an Amex-related promotion (e.g., #AmexWholeFoods, to receive $25 off a $75 purchase at Whole Foods).
Micro-affiliates | JWT Intelligence