Spays is a payment system that designed for companies operating in part-deficiency markets. System allows do not stop sales without offers, but increase the price to make it available all the time.
For example, Thai airlines has 500 tickets from Beijing to Bangkok in May and sold them out on April, 15. Tickets sales have stopped.
! Spays allows to keep 1 or more tickets in sales, so people may outbid it with more expensive price yet plane not take off.