You're right, but there's a catch-22: my wife and I are starting a company focusing on helping people move to other countries. For recruiting, we currently only work with companies who sponsor work permits and help with relocation. Thus, I act as a recruiter for those companies and if I mention their names or get too specific about what they do, candidates can apply directly. That not only removes any commission we make referring them, it also kills any chance we have to help the candidate prepare for the interviews.
I am very passionate about helping people become expats (my wife and I have both lived in multiple countries) and I'm just hoping I can find a way to turn my passion into a business.