Tons of companies print their own money. It's just called "miles", "points", "coupons", "credits", etc. - but it is a medium of exchange that can be used to buy

Tons of companies print their own money. It's just called "miles", "points", "coupons", "credits", etc. - but it is a medium of exchange that can be used to buy stuff at this company, i.e. money. Of course, airline workers would never agree to be paid entirely in miles, but probably would not mind getting their hands on some more of them.