While several US-based sites like Facebook and Twitter might get most of the publicity, social networking is a worldwide phenomenon that eMarketer predicts will encompass nearly 1.5 billion internet users by the end of this year.As of December 2011, eMarketer estimates, just over 1.2 billion people around the world used social networking sites at least once per month. That represented 23.1% growth over 2010, and double-digit growth will continue throughout eMarketer’s forecast period, though the rate of change will decrease as the market matures.

via Where in the World Are the Hottest Social Networking Countries? – eMarketer.