My aunt and uncle run a placement company for high end medical jobs. Very specialized. Kind of a nitch field I guess. Although I dont know too much about it, I know they make bank. But its a who you know bussiness, which she has been at it for a long time; HR related. and my uncle was in the medical field for a while too. the two put it together and this is what they got.
I am not sure what you would have to insure. If your talking a head hunter type company, its mostly up to your client being honest with his skills and resume, not being a total tard and you helping them with interview skills, and finding roles they could fill correctly. Its seems like a very good idea, and with all the information on the internet and such, very little overhead expense. once you know others like you doing this, “work” together you send one their way they send you some your way kind of thing.