Estimated at $46.8 million in 2006, this market will grow to $428.3 million by 2009 “creating a new application segment and establishing social networking as a new communications tool used for many purposes other than consumer socializing.”

IDC identifies three social networking segments emerging:

self-service applications used by groups and marketing campaign teams; brand applications that focus on persistent customer engagement; and enterprise applications that provide more effective ways of working with customers, partners, and other external parties.

Other key findings of the study include:

• The social networking applications market will grow quickly over the next three years and continue to grow, but at a slower pace, after 2011.
• Social networking application vendors will continue to emerge over the next two years, particularly those focused on vertical applications.
• As the market develops, social networking functionality will be built into core communication platforms like email and instant messaging (IM) applications and the market, particularly the enterprise segment, will consolidate.

According to IDC, around 45 % of businesses in the US already use a Web 2.0 tool such as a blog, wiki, chat or forum, and more than 30 % use blogs for internal company communications and collaboration, and to communicate with their customers.