A CMO's Guide To The Social Media Landscape | CMO.com
http://www.cmo.com/social-media/cmos-guide-social-media-landscape

Social media marketing is expected to dominate this year -- but the growing list of online social media sites makes choosing the right route complicated. From Facebook to YouTube to Digg and beyond, which media outlets will net the most bang for the buck in terms of customer communication, brand exposure, traffic, and search engine optimization (SEO)? Includes a downloadable PDF version of a chart on leveraging social media options