Foursquare Tops 15 Million UsersFoursquare now has 15 million users, tripling its base since this time last year. Half of the users are in the U.S., while the other 50 percent are international. The New York-based tech company revealed the stats to ClickZ News in a pair of emails on Monday. Foursquare's new high-water mark underscores how the geo-social startup scene has moved forward even while enduring growing pains in 2011. T
