A coupon is distributed to each consumer who spread the word.
A gift is offered when customers share the offer.
X consumers say they are interested by the product. The more they are, the more the price decreases during the campaign. At the end, they can buy the product with the discount they have winned all together.
The customer is rewarded for each share of one of its followers or Facebook friend
Followers / fans acquisition
During a specific campaign, reward each new follower or fan to grow your community.