The document discusses location-based services (LBS) that utilize GPS technology to allow users to share and discover their real-time locations through mobile devices. It highlights the value for users, including incentives and social interactions, as well as current demographics with 4% of online adults using LBS, primarily among younger and Hispanic populations. The document also reviews various LBS platforms like Foursquare, Gowalla, and Facebook Places, examining their features, user engagement, and promotional outcomes.