sharing comments about your visitings: foursquare

Foursquare is an interesting application. It is relatively a new idea. Increasing number of mobile users using internet (thanks to 3G) and GPS needs new ways of getting most out of their mobile devices. GPS assisted mobile device users benefit of navigation and maps. Foursquare is not about navigation but is about the places you visit. Foursquare user visits different places (cafe, bar, restaurant, airport, etc) and comments on the service quality, foods, beverages, etc. The more you visit the same place, you become the mayor and might get special offers and discounts. You can watch this short video to get introduced to Foursquare.
http://www.howcast.com/videos/386406-How-To-Unlock-Your-World-With-Fours...

On the other side, Foursquare collects information about your visits and of course your personal information. They know where you have been at a given time. More you use Foursquare, they can better analyze your behavior and identify what you like most or what you don't like. This type of data can be easily used for targeted advertisement. You can even cluster people according to their behaviors and ages. As it is clearly stated in their policy, they don't sell your data but they share it with the businesses that they are affiliated. What does that really mean? They don't sell it simply because they don't need to. Good news is they already get affiliated.
To sum up, Foursquare is a nice application, it is good to share what you like with your friends but the collected data reveal valuable information and they clearly state that they share your data with their agents and other third parties that they are in touch.