54 percent of the Fortune 100 have a Twitter presence, 32 percent have a blog, and 29 percent have an active Facebook Page. Moreover, at companies using only one of these tools, at 76 percent of them, the tool of choice is Twitter. Of the Fortune 100 companies on Twitter, 94 percent use it for news/announcements, 67 percent for customers service, and 57 percent for deals and promotions. The average Fortune 100 Twitter account has 5,234 followers. More stats and the complete presentation of the Burson-Marsteller study at Mashable.