Extremely fine effort. Also worth useful article. too. I just use facebook for my business by creating custom fan page. I got good results too. social media marketing | social media marketing company
I am using Facebook, Twitter, Youtube, Hacker News, Digg and Diggo. Myself am using LinkedIn, but frankly did not ever got any traffic from it. Yes get lot of friend requests and event program invites, but online marketing from it, never thought of it.