Excerpts from Quint Careers:
Career experts estimate that the vast majority of job openings are never advertised or publicly announced, but filled through word-of-mouth or networking -- known as the "hidden job market." The likelihood of a job opening not being advertised at all increases with the level of the job. Yet, even with this knowledge, most job seekers fail to fully utilize networking for all it's worth.
Networking means developing a broad list of contacts -- people you've met through various social and business functions -- and using them to your advantage when you look for a job. People in your network may be able to give you job leads, offer you advice and information about a particular company or industry, and introduce you to other so that you can expand your network.
Read the full article for more tips here.