This document discusses location-based social networks and focuses on Foursquare. It provides an overview of Foursquare, including its popularity and user base. It then describes how businesses can use Foursquare's Merchant and Brand Platforms to find new customers, create special offers to drive check-ins, and access customer data. Case studies show how businesses have successfully used Foursquare to increase sales and brand followers. While offering opportunities, the document notes privacy concerns about check-ins and competition from other location apps and services.