Last night, the local news had a piece about the "hidden job market." You know, the one that you can only get to if you know the right people, wear the right tie, have the right golf handicap, etc.
The truth is... it's not hidden. It goes back to folks prefering to work with those where they'll have a greater chance of building a solid relationship. (see Nov posting "Please Like Me").
And how do folks start to feel like that chance exists? Through recommendations from other people in their networks/communities. So if you are networking, chances are greater that you will be recommended. Simple.
Look at it this way... If you wanted to borrow a car for a day - would you get more results from cold calling strangers with your driving record or from calling those who already know you and would be willing to recommend you to a friend with a car?
So the market is only "hidden" if someone isn't participating in their communities. That takes time and effort.
Don't worry about not knowing the "right people"; there aren't only 12 'right' people out there to know. Get your reputation out there in advance - open more doors - target key players you genuinely admire - champion others, ask them to champion you. That's the real market. That's wide open to all comers.