Originally Posted by
huicity
Thanks for all the answers thus far. I've pretty much given up on the 100 hour rule for early confirmation using 500 mile cert upgrades, and when the upgrade does happen, it's usually the day of (though I've been surprised every now and then).
Typically when I sit in First Class, i'll chat with my seatmate, and often times i'm not sitting next to high UA status folks, so there's gotta be something else going on.
I have noticed this year that whenever my upgrade does not clear at the 100 hour window, the number of available seats for sale in coach is somewhere between 0 and 6. For example, last week between IAD and BOS, the 757 seating map show 19 open seats in first and nothing was available in coach. My upgrade didn't clear until a few hours before flight time. This pattern has occurred at least three or four other times this year - i.e. tons of empty seats in first but nothing left in coach - the upgrade then clears a few hours before flight time. I also note that if Orbitz or UAL or Expedia allows a coach class booking at a high price (but not at the same price as first class) the seat map only shows first class availability.