From: Tom Woolnough: http://onthesource.blogspot.ca/…/stripping-linkedin-profile…
Dark Matter, as Glen Cathey describes it, are the thousands of profiles which a standard LinkedIn search will not bring up.
These profiles are missed by basic searches because they don't contain the right keywords or they have very skimpy, incomplete profiles (often on purpose).
Here's how to solve that problem. Get the profile of a candidate you know to be a superstar. Copy his job title and past company into a search, and run through all those doing that job.
The real gems here are the ones with no information filled in on their profile; the kind you would never have found with your standard search, because by doing any kind of search other than the name of the company you are excluding them entirely.