Bullhorn, a technology powerhouse in the staffing space, has been pushing into social media in a big way. Monday, it released Bullhorn Reach from beta, four months and 10,000 registered users after launch. As I detailed a few months ago, Reach does a lot of the same automating and posting of jobs to social sites that other services do, but it also tracks what the people in your network are doing and alerts you to the possibility they may be preparing to “go active” in their job search.