Hello! Users share their background location with us as they explore the world with our city guide app, Foursquare, as well as our check-in app, Swarm—so it’s based on people’s foot traffic, not check-ins. We anonymize our location intelligence data and analyze it in the aggregate, then normalize it against the U.S. census to ensure there is no bias. And then we make our cool charts and predictions. It’s pretty powerful, don’t you think?