It isnt really a problem that affects me, but its a good idea.
If they want, they can work for peanuts for long hours, but in return they get a roof over their heads, and food. The only thing is, they can't ask for pay rises and they have to kind of obey the master a bit.
But they aren't forced to do it. They get into it if they want to. They can leave when they want to as well.
Pretty much perfect?