Foursquare now has roughly one million users. If you haven’t heard of it, it’s a location-based social network, software for mobile devices, and a game rolled into one. Users “check-in” at specific venues (i.e. restaurants, coffee shops, or other retail locations) using text messages or apps on smart phones. People are awarded points and badges. Whomever has checked in the most at a specific location becomes the “mayor”.I’ve been using foursquare for several months now. I’m impressed more with its potential than with the actual functionality. I’ve got to admit that it fun to “check in” places, get points, badges, and become mayor. The game aspect of Foursquare stirs my competitive nature. It’s fun, but I see this as a bit of a novelty. I’ve already seen a steep drop-off of check-ins from the early adopters of foursquare whose check-ins would show up incessantly in my twitter feed just a few months ago. The network was adopted readily at first. Earlier this year I would receive 5 or more invitations to foursquare daily, now I receive one or two a week. In order to retain its users, foursquare will have to add functionality and new ways to interact. Built into foursquare is the ability for businesses to offer discounts and specials for people based on the number of check-ins (the discount and the number of check-ins can be adjusted), but this is just the tip of the iceberg of marketing potential for this network. I still think there is a huge un-tapped potential here for marketers and I’m looking forward to the creativity that can be unleashed on foursquare and other location-based social networks. Like most things in the U.S., New York City is leading the way in marketing innovation with foursquare. The following post gives some good examples for successes: How NYC businesses are using FourSquare to drive more customers I’d love to hear any ideas or examples of success with foursquare, (or other location-based networks) that you could share….