Recruiters see people. Job Boards see database matches. Recruiters talk to people who aren't looking. The Job Board Network is a room full of computers. The Recruiter's Network is a Rolodex of phone numbers.
Recruiters invest heavily in relationships with people.
Job Boards invest heavily in relational databases. The Web Revolution will take a decade or so. We're just finishing the first phase. As we move forward, the essence of Recruiting will start to really find its way online. Price points will rise as the level of intimacy rises.