Remember back when the next big thing was check-ins? It was back around 2010, there were multiple applications for checking in, and there was so much imagined potential for space. Even Facebook and Yelp decided to try and scoop up some of the action. And one-by-one, from the Foursquare competitors to Facebook places, they've disappeared.
For whatever reason, be it user interface, brand loyalty, or just the way things go, Foursqure held out. They held out as people tried other platforms but didn't switch. They held out through the time when the big dog, the 800lb gorilla of Facebook tried to use its giant user base to muscle them out of the space. They held out as location and recommendation engine Yelp parroted their concepts of Mayor with Duke and Duchess of check-ins.
Through it all, Foursquare was still "the Check-in app".
Until Foursquare decided to do what none of their competitors could do -- move check-ins into a competitive app (Swarm) and get Foursquare out of the check-in business.
It's so mind blowing, it almost seems comic, like a scene from a Marx Brothers movie. "The plane is carrying too much weight, we're going to crash. Find something to throw overboard... How about this engine? Too much weight, get rid of it." Of course, that whole scene would still resolve with a happy, funny ending.