Social media use by Fortune 500 companies - 62% use Twitter, 58% Facebook, and 23% have a blog

"A recent study from the University of Massachusetts at Dartmouth has found the adoption of social media usage among Fortune 500 companies has levelled off. Across multiple industries, usage of Twitter, Facebook and blogs in 2011 is level with or below that of 2010.
In 2010, 23 percent of Fortune 500 companies had a blog. In 2011, that figured remained unchanged at 23 percent. In 2010, 60 percent of Fortune 500 companies have a Twitter account. In 2011, 62 percent have an account. In 2010, 56 percent of Fortune 500 companies had a Facebook account. In 2011, 58 percent have an account."

Source:  Data from the University of Massachusetts at Dartmouth, reported by Adrants, 2nd November 2011