Legitimate vs. Non-legitimate is bullshit.
Legitimate (meaning you pay facebook) is still shit, because there are many robots out there that are friends with you/friends with your friends/in your targeted location AND they will actually like your paid ads just to make themselves look real. So.... why the fuk pay facebook for fake ass leads.
You want proof? Run an event that targeted people in a certain location and make the objective RSVP responses. Check how many RSVP's you get (there will be a lot!), but when the event time comes or when you dig a little deeper into who RSVP'd, etc.. you will notice that 85% are BULLSHIT and are fake profiles.
Don't give facebook your money!