Pick up your smartphone. Search through some of your favorite apps. Do you have Uber? Maybe Foodspotting? Surely you have Instagram. These apps, as well as a significant amount of the most popular apps in Apple’s App Store and Google Play, use Foursquare location data. For developers who have user actions or content tied to Foursquare venue IDs it would be difficult (if not impossible in some cases) to migrate their services off the Foursquare location database.

via Foursquare’s API Is A Pillar Of The Mobile App Ecosystem | TechCrunch.