Put here so I can think about it. from the B2C (business to community) blog
Aided in part by greater access to the Internet and mobile devices, social media usage continues to grow in breadth and sophistication. An interesting by-product of this growth, a social media classification system is emerging based largely on functionality rather than user demographics.
Read more at http://www.business2community.com/social-media/insight-into-the-emerging-taxonomy-of-social-media-0247753#bfz3qwDw3fLZEMF2.99