Nancy Miller, writing for Entrepreneur magazine, fills in some of the backstory on last week's Foursquare product announcement:
...the two new leaders began diving further into all the valuable data Foursquare wasn’t putting to use. There was plenty. Asset number one: The more than 11 billion check-ins tracking people in real life since 2009. Asset number two: The four million monthly updates to its Places database -- changes in address, phone number, a Japanese restaurant that was now a spaghetti joint. And then there was the sleeper, asset number three: 100,000 developers tapping into the Foursquare API -- its location technology -- for free. Enormous companies like Yahoo and Pinterest were using it a billion times a year; for example, when you pin a photo in Pinterest and tag its location, that’s using Foursquare’s data. But Foursquare had never asked these companies to pay.
Yahoo and Pinterest were using Foursquare's location data a billion times a year and no one had asked them to pay. One reason is that Foursquare thinks of themselves first and foremost as a consumer-facing product organization. But it's still surprising to learn that they weren't charging for this data access.