Gowalla did not work with Foursquare on this integration; it was all done through the API. That leaves the real possibility that Foursquare could throw a big wrench into Gowalla’s plans by blocking its rival’s use of the API. The threat posed by Gowalla 3 is real; that alone could force Foursquare’s hand in the name of competition. It would also create a firestorm of controversy.
