You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract Digital Marketing Guide: Social Media What's the Next Twitter, Do I Have to Follow Shaq and Who Should Tweet for My Brand? By David Berkowitz, Published on February 22, 2010 4 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.