ny times posts
Now, some first-class seats not sold at the usual prices as departure approaches are being offered instead to coach passengers at check-in time, at discount prices.
As someone without elite status on any airline, I selfishly welcomed this trend on a recent flight on American Airlines from New Orleans to Dallas on a basic coach ticket. At check-in, a box popped up on my computer offering me a seat in first class for a mere $45 extra. I went for it because I had a checked bag that would have cost me $25 on my coach ticket but would be free in first class. As a result, that first-class upgrade actually cost me $20. Still, in another time, the first-class seat that I bought so cheaply would most likely have been awarded as a free upgrade to a coach passenger who had elite status.
http://www.nytimes.com/2014/06/17/business/17road.html