Allfacebook.com has a story that Facebook is testing out allowing businesses to promote offers or discounts when people (either individually or with friends depending on the criteria set) sign into a Facebook Place.
“As the image below depicts, this company (who’s identity is being hidden to protect them) has had their first deal approved. The deal involves rewarding a Facebook user with a free product when 3 of a user’s friends are tagged at a specific place. The creators of deals can determine the threshold required to earn a deal. One of the major criticisms of many of the existing check-in services (Foursquare, Gowalla, and even Facebook) is the lack of incentives for checking in to various locations.”
Source: Allfacebook.com