Foursquare doesn't just allow users to be 'mayor' of a coffee shop they frequent - it's also a great tool for business. Foursquare allows users to 'check in,' every time they visit a venue in real life, and records it both on Foursquare and other social media accounts like Facebook and Twitter (if these accounts have been linked). Brick-and-mortar businesses can offer specials through Foursquare, like rewarding the number of times a customer checks in, making it a great tool for customer loyalty. Venues can also offer other types of discounts, like coupons, to their Foursquare followers. For brands who don't have a brick-and-mortar presence, Foursquare does offer a few options, like check-in specials for when the brand partners with a brick-and-mortar retailer, and badges, which allow customers to complete real-world check-in quests that can get them rewards from the brand.
To learn more about Foursquare for your business, you can visit the Foursquare for Business website, or you can watch this awesome video.