To what value Social Networking

What to do first. Blog, Tweet, Facebook, Linkedin, call prospects, send out marketing letters, Groups sites that you are part of, email. All are good tools to further extend your social and business network. The question is are they bringing direct results to your bottom line. How can it be monetized? I've been at the above for the last 2 hours. Been pretty busy but how do you quantify it. So I'll leave it with that and move on for now.