Top location check-in service Foursquare announces it now has 20M users (up from 10M in June),...

|By:, SA News Editor

Top location check-in service Foursquare announces it now has 20M users (up from 10M in June), and that it has seen over 2B check-ins. Facebook (FB), about to be free of the SEC's 500-shareholder rule and apparently willing to shell out to acquire a market-leading rival, might be playing close attention. Foursquare obtained $50M in funding in June at a $600M valuation. (also)