Foursquare is a location-based social media app launched in 2009. It allows users to "check-in" at locations and earn points and badges. Starbucks partnered with Foursquare for a successful promotional campaign. The campaign offered $1 discounts to Foursquare mayors who checked in at Starbucks locations. It also donated $1 to charity for every check-in. The campaign was very successful, driving increased revenue and brand awareness for Starbucks while raising over $10 million for charity.