One of the newer additions to social media is Foursquare. This basic concept is that people check in when they are visiting places such as cafes shops etc and the person who visits the one place the most becomes the mayor of that place. To learn more look at this website http://foursquare.com/businesses/
Some businesses are using this concept to their advantage by creating added value for people who use the foursquare concept. This builds your current customers in to more loyal customers and can also attract new customers.
One icecream shop gave the mayor for each day a free icecream and increased their business substantially. If there is a choice between shops and you may get something extra from one place then it is most likely you will choose that place.
Another example is a hotel who offer a bar discount to their patrons who check in on four square http://www.hotelworldnetwork.com/customer-loyalty-programs/aloft-introduces-social-networking-rewards-9746
All these things create loyalty with customers and increase your exposure on the web. What can you do with this type of advertising media to improve your business?