Foursquare is a location-based social media app launched in 2009. It allows users to "check-in" at locations and earn points and badges. Companies like Starbucks have partnered with Foursquare to run successful promotional campaigns. Starbucks offered $1 discounts to Foursquare mayors who checked in. The campaign increased Starbucks revenue and also raised $1 million for charity. It improved Starbucks' social media presence and brand image.