This document discusses Foursquare, a location-based social networking app that allows users to "check in" at locations using their mobile phones. It provides an overview of Foursquare's features and functionality, how merchants have adopted it in Singapore by offering rewards to Mayors, and opportunities for American Express to engage with Foursquare users through local events and influencers to promote merchant partnerships. The document contains confidential strategies and must not be reproduced without permission.