There’s the obvious reason Facebook would pay $1 billion for Instagram: the mobile app, with its 33 million users and recent expansion to Android, was a growing threat to Facebook’s spot as the largest photo-sharing service in the world. But Lauren Goode at AllThingsD points out that Facebook gets something else in the deal in addition to Instagram’s easy interface. Instagram also makes it very simple to automatically tag the location of your photos. Some users have complained that it’s too easy—that it’s hard to know when your location is being automatically shared. Facebook has repeatedly tried and failed to get more of its users to post their location.