> You do something that is sold for X and you are paid X-Y.
If my neighbor wants a new fence (the Y), offers me $50 to dig a hole (the X-Y) to put a fence pole in.
I dig a hole, i get $50. He gets closer to a fence. we have both profited, who is exploited?
Or if you want to go even more basic:
he wants a fence, he pays me $500 to build a fence, i build the fence and get $500. who is exploited?
Note these are real examples from real life that i deal with.