1) Location-based marketing is growing rapidly due to the proliferation of smartphones, GPS devices, and faster internet connections. Services like Foursquare are gaining users twice as fast as Twitter. 2) Location data provides value to both consumers and businesses. For consumers, it enables networking, discovery of deals and events, and gamification. For businesses, it allows targeted digital content and offers to invite consumer spending. 3) Major players in this space include Foursquare, Facebook Places, Gowalla, and new entrants focused on specific use cases or verticals. Emerging models include implicit location sharing and team-based game mechanics. 4) Effective campaigns integrate location data into welcome messages, offers, content