Four multi-billion dollar B2C brands that still aren't on social media: http://mashable.com/2012/12/03/brands-not-on-social-media/
Mary Meeker of Kleiner Perkins publishes "2012 Internet Trends Year-End Update": http://venturebeat.com/2012/12/03/mary-meeker-releases-stunning-data-on-the-state-of-the-internet/
Facebook probably isn't buying WhatsApp, but seems to start competing with it: http://techcrunch.com/2012/12/04/messenger-no-facebook-account/
And Facebook's democracy experiment is drawing to a close: http://readwrite.com/2012/12/04/facebook-asks-users-to-vote-on-whether-users-can-vote
Leap Commerce hopes to figure out social buying: http://allthingsd.com/20121203/new-leap-commerce-app-hoping-to-spark-conversations-about-shopping/?refcat=social