As I became mayor of a local restaurant on FourSquare and it was sent out via Twitter I was asked what value I get from that? Well some of the restaurants are grabbing ahold of driving in person traffic and the game that FourSquare has become.
Let me explain further. A restaurant sees, sometimes accidentally, that people are checking in (via FourSquare or Brightkite or whatever) to their restaurant. This then shows to their friends and followers where they are and a place they eat often. Most restaurants get business from word of mouth, not just random stopping by. So to have those people continue to patronize the location, they offer coupons for that day via Twitter (see my posting from March 09).
Then along comes services like FourSquare that take location awareness to a game level. By checking into a place often enough, you can become the mayor of the location. No matter what it is. Wayne Sutton became mayor of his hotel room in Vegas at BlogWorldExpo humorously. So the restaurant rethinks some of the strategy and gives free drinks (or maybe a small dessert or salad, whatever) to the current mayor of the location. The person is there spending enough money and announcing where they eat, so this becomes a frequent visitor/diner card without the card.
How do you, the user, capitalize? Look for places that have offerings that you frequently visit. Point out to the owners of some of these local delis, cafes and more about the ability to maximize patronage without extra advertising budget. Look at what Rizzo Tees in St Louis does via Twitter to drive traffic. Chris does an amazing job with offers, coupons and specials and has a large following.
Forgot the crazy thought about having a coupon show up as you walk by a place, most of us already have a destination in mind and there is so much more integration to be done there first with GPS. This side lets the customer be the word of mouth.