I have applied to them and their sister company GAAP Recruiting. I have the same question. They seem to have a lot of jobs in the field I am in and they seem to pay suspiciously well.
Their application is a pain. Even when you get it to work you almost always getting an email telling you to go back and finish the application (which signaled you at the time that you had completed and submitted it). I never hear anything from them. I have written and called, but nothing.
If they are not legit, I can't figure out what their game is.
Has anyone every gotten an interview from one of their applications? I would really like to know.