You have chosen to sponsor your bid up to a maximum amount of .
Essentially, they will be able to give credits or discounts for users sharing their order with friends on facebook, twitter, etc
So, for example, a customer who buys a TV could be incentivized to buy a Blu-ray player with an offer of 50% off if they share a related offer with their social network, say 20% off for ‘friends and family’. Thus the retailer gains exposure to new potential visitors, leading to more sales, while the customer gets something in return, which could be in the form of a discount code, free delivery or cash back. Offers can be tailored accordingly.