By YOUNG MONEY Staff
19 July 2010

Foursquare, if an iPhone-toting friend hasn't yet informed you, is what is known as a "geolocation social networking app." In plain English, it tells all your friends where you are whenever you want. At the bar? Watching the game? Chilling on your porch? Foursquare lets you "check in" to different locations, and people with the most check-ins can earn titles and rewards.

A neat toy, but where does the entrepreneurial angle come in? Why did Inc. select Naveen Selvadurai as its top young entrepreneur?

Well, as it turns out customer loyalty is actually pretty big business. Local stores can offer coupons and deals for users who check in frequently, and bigger companies can actually push advertising and sponsorship through the app, alerting users to discounts and sales.

Starbucks, for instance, offered $1 off of Frappucino drinks for a month to the "mayor" of every Starbucks - the person with the most check-ins.

That business savvy got founders Selvadurai and Dennis Crowley $20 million in capital investment in June. Unlike many clever, popular web applications - here's looking at you, Twitter - Foursquare has already integrated itself with business and entrepreneurial ventures, making profitability a priority alongside engineering.

Selvadurai and Foursquare are planning a major overhaul of the system this summer, and membership is growing by 100,000 a week, according to Inc. For now, then, Selvadurai is living the young entrepreneur's dream.