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 There Are 181,000 Social Media 'Gurus,' 'Ninjas,' 'Masters,' and 'Mavens' on Twitter A Growth Industry: That's Up From Just 16,000 In 2009 By B.L. Ochman, Published on January 07, 2013 18 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.