I think they'd have to be compensated in some way. Can't hold down and 9-to-5 and then come home and help people find their loved ones. So there would be professionals who would make their living as such. Then you'd have the good ones who would command more money because they have the stronger force.
Those great ones would need a staff and bodyguards, perhaps a location and advertising. The staff, taxes, building, p.r., need to be paid so commercials to draw more business is inevitable.
It's not unethical, it's just business.
Pastors are paid a salary. Shouldn't they spread the word of God for free? Gotta eat.