The only way to make money is to convince people to give you money. If you wanna do it by acting like it's because of some skill you have, that can work.
Producing value gives leverage. A salesman who brings in lots of revenue and profit can negotiate a pretty high commission, because controlling that level of revenue/profit represents some leverage.
To the person he exercises leverage over, who makes money on each sale made, and pays his wages/commissions? Isn't that obvious? He agrees to sell some stuff, in exchange for money that comes from the sale.