http://en-us.nielsen.com/main/insights/consumer_insight/september_2009/asocialmediahowtoforretailers

“The social media frenzy—also known as consumer-generated media (CGM)—refers to content being created 24-hours a day online on blogs, message boards, social networks like Facebook and platforms like Twitter. CGM has come a long way from the early newsgroup days and continues to grow rapidly.”