As an employer, I want to hire the best people so my company can be successful. Why would I hire anyone from your site when there are plenty of other candidates elsewhere?
Do you think people will try to use your site to disqualify potential hires (i.e. use it as a do-not-hire list so those registered with the site can specifically be avoided)? How will you prevent this from occurring?
Why would a company that doesn't care about criminal records advertise with you? Wouldn't it make more sense for them to advertise on a generic job board, take the best resumes, and sort out criminal history issues as they arise?
Does your site allow employers to see what a job seeker's crime was, or any other info related to that that other job boards wouldn't provide?
Not associated with that company but one reason to hire a convict is that you get a pretty decent tax break[0] out of it