FOAF -style Network

What professional benefits do you see by investing time into a FOAF-style network?

Friend of a Friend style networks have become increasingly popular throughout the years. There are social media networks such as Facebook, Twitter, LinkedIn, and MySpace that all use this FOAF style network. For example, when you sign on Facebook in the upper left hand corner they suggest friends for you that your friends are friends with. This could be professionally beneficial on sites such as LinkedIn because you can upload your resume and professionally network that way instead of attending a conference. An example of how this may be professionally beneficial comes first hand from one of my marketing professors. She decided to follow a woman at the local newspaper on Twitter, when my professor had to go out of town she asked the woman from the newspaper to come in and talk to our class about press releases and additional PR. If it weren't for Twitter these people would have never professionally met.