BUT I don't understand where does the money for the rewards come from? ''Who'' pays these rewards?
Of course, as in any pyramid, at the expense of the influx of new users. Remuneration is paid from the cash flows that come into the project from the registration of new participants and the marketplace, because participation is not free and you need to buy sneakers, that is, you need initial investments to make money. That's at the expense of them, and formed the rewards for other participants.
This thing is not eternal and sooner or later, as with any pyramid scheme, there is not enough money for everyone and it can turn into a scam.