The most targeted: Twitter and LinkedIn, with over 60% using each of them, beating out Google+ and Facebook, neither of which cleared the 50% level. And Digimind report indicates this is not used solely for B2C (business to consumer) research.
What does that mean to you? If you are not using social media (which is free, or at least cheap) to outsmart your competition, you could be missing out on a lot. And you do not have to have years of training to do that – all you have to do is read!