Few remember the old days when recruiting and advertising of jobs happened almost exclusively through newspapers.
Then came the Internet and the era of 'Monster' job boards that allowed employers to instantly post jobs for all to see in a single place. It allowed people to check out jobs and apply online or just post your resume and wait to be found by an employer that is looking. This made the process very efficient compared to the newspapers. Can you imagine writing a resume and cover letter, printing it out and mailing in an application just to be considered? The speed, low cost and efficency of the Internet and job boards is one of the main reasons (the same thing happened with News) why newspapers failed/are failing rapidly to attract any job advertisers.
Social Networking, which has taken more than 10 years from the advent of the Internet to finally catch on is now starting to seriously impact Recruiting again. People are increasingly comfortable sharing what they do for a living on their socially available profiles on Linkedin, Facebook, etc. Recruiters don't need to wait to find their resumes on a job board anymore. They can access the entire passive candidate database to look for a fit, which they could never do previously and make a warm harmless introduction.
This is not bad for candidates either. No longer do they need to post their resume on a job board to test the market or indicate their intention to check out new opportunities. Social Networks are exposing them to opportunities even when they are not looking for jobs. People can easily see whats going on at various companies and with people they are connected to, sense market conditions and are more open to talk to recruiters about new opportunities.
This big change that is happening (this time in expanding the candidate pool) again significantly increases the efficiency of matching a job seeker and recruiter and therefore if history is a teacher, it seems very likely, the social networks will do to job boards- what the job boards did to the newspapers. Watch out Job boards! The times they are a changing.