Как авиакомпании зарабатывают на милях и т.д (eng)
 

"As of the end of last year, there were 17 TRILLION unredeemed frequent-flier miles, and the number grows by the millions every day. Some have argued that the real value of these miles is over $480 billion. Its a 16-year inventory that airlines know they cant or wont redeem.....""Want the real insult? Assuming an airline does, in fact, redeem your mileage for a ticket, the actual average cost to the airline to do so is slightly more than $23. Thats it. Just $23. Now you can understand how wildly profitable these programs are..."Статья полностью - msnbc.msn.com/id/23137092/