This document provides a summary of major social media sites in 2011 and how they can be leveraged by companies for customer communication, brand exposure, traffic generation, and search engine optimization. Each site is rated as good, okay, or bad for these categories. Key points include that Facebook is best for customer communication, Twitter for outbound messaging, Flickr and YouTube for quality images and video, and Digg and StumbleUpon for content discovery and viral traffic potential. LinkedIn is highlighted as useful for personal and company branding.