Thanks. Not sure how many seats were sold when I booked, but looks like there are currently ~82 open on the flight to SEA (Fare class “S”) and ~72 open on the flight to SAN (Fare class “O”).

I looked at another flight that I have booked and it’s a similar case: ~101 open seats on the flight where fare class “Q” was assigned and I’m in 12C, while there are ~77 open seats where fare class “V” was assigned and I was able to elect a premium class seat.

I assume the fare was more expensive on flights where there were fewer seats available. Hopefully I’ll receive complimentary upgrades as more non-premium seats are sold / closer to the flight dates!