Business Insider had published an article about "How LinkedIn Plans To Grow Its Biggest Business 1,100%"
As for matching job seekers with employers, the best predictor of job performance is: personality!!!
See paper: "Workers Behaving Badly: Personality at Age 18 Predicts Workplace Deviance at Age 32" by Dr. Kimdy Le
LinkedIn should include a personality test like the 16PF5 to assess personality of applicants.