Originally Posted by dave h.

are free C+ upgrades something normal or just a glitch?

while planing an upcoming trip for a few months, i was following prices for SEA-HKG. it was $500 for a few weeks with the C+ upgrade at $100. at 90 days out the ticket price went to $1100 (C+ went up to $170), then a week later went back down to $500. but the C+ price stayed at $170. so i booked it while it was cheap again and picked my seat, then paid for the C+ and changed seats.

immediately after this i paid $2200 for LHR-SEA and picked my seat. when i looked at the C+ window, it said "FREE Upgrade". i clicked it and changed my seat and it went through, no extra charge.

was the free C+ a glitch? or maybe because of what i paid for the first C+? or just Delta being nice?