Here is a link from a recent NY Times article on various job search methods. There is some confirmation for LinkedIn from the perspective of recruiters.
http://www.nytimes.com/2008/09/27/business/yourmoney/27shortcuts.html?pagewanted=1&_r=1&em&adxnnl=1&adxnnlx=1222977789-dgl0WtFSCWfqY8duvQoDgg
Can You Guess What Word This Post Is About?
9 years ago