Will Southwest's No Cash Policy Work?

It was announced earlier today that Southwest Airlines is going to stop taking cash for alcohol on flights. Instead, they are going to start taking debit and credit cards along with the rewards coupons that will still be in effect. The good news is that it will do away with flight attendants frantically asking if anyone has change for a twenty. But will it speed up thing, make things slower or just be status quo. I have a hard time seeing them doing on the spot transactions with a credit card machine while in the air. So look forward to some sort of method where they are going to have to record the card number, have you sign and then not see the $4 charge show up for a day or two after your flight. This system could drive a few people to not buy that drink while at the same time others who don't like to carry cash see this as a good thing. Either way, starting September 9th those of us that fly Southwest will get to see first hand just how it all is going to work. I will have my rewards coupons with me though.