> It works because everyone in the game has something to gain from it

It's reminiscent of triangulation fraud in that regard. The incentive is for everyone involved to keep their mouths shut because you buy something for below-market prices on sites like eBay, the "seller" places orders using stolen credit and debit cards with legitimate retailers, and the product ships directly to you. Everyone wins...as long as the account holder doesn't pay attention to their statements.