Why didn’t the airlines think of this sooner (or did they)? Delta will be selling upgrades to first class at the gate, subject to availability of course. They are priced according to flight distance. Although budget travelers may not spring for the opportunity, many will find it an enticement as it appeals to a traveler’s psychology. It spreads out the spending of money and is a much easier splurge to make then when you are buying your original tickets, especially if you’re sitting right there, hungry and tired, unhappy from traveling. It’s also a great enticement for business travelers whose companies paid for their original coach ticket. Unfortunately, the losers are probably those with frequent flier upgrades, though Delta says the most frequent fliers will still get priority on upgrade requests.