It starts by getting these Semi-Passive candidates attracted to your opportunity. Once at your site candidates can anonymously register and be apprised via emails of other opportunities as they arise. You still need to get candidates to your site and you need to keep them there with good content and a real vision. The regular emails keeps them coming back for more. That's why they're called sticky sites.
Most job boards offer a similar email job agent.
Content and community is the newest trend being used to capture these semi-passive job seekers. Through active discussion groups, Vaultreports offer inside information about the real culture of the Fortune 1000. Don't be fooled. When many eCruiting software vendors or sites talk about having the ability to find the passive candidates they are not referring to these people. They want you to think this is their target audience, but in reality it's the Active and Semi-Passive .