BK Sacrifice
Drop 10 friends from your Facebook account, get a free BK Whopper. AdWeek story: "The fast-food chain has released the Whopper Sacrifice application on Facebook. The app rewards people with a coupon for BK's signature burger when they cull 10 friends. Each time a friend is excommunicated, the application sends a notification to the banished party via Facebook's news feed explaining that the user's love for the unlucky soul is less than his or her zeal for the Whopper."