curious about nexon's cash cow (cubes)

but every 1000NX used gets Nexon $1 richer, so year, confused.

Doesn't matter if the NX gets used, they still got the money. As if you got free NX, it doesn't matter to them because it's not like they lose when they give out NX. There's always going to be unlimited amounts of everything in the Cash Shop, unless there's an event or something (once a day things).