Part of the problem is that my travel plans do not neatly fit into one airline from SFO. I take AS from either SFO or OAK to ANC once a quarter, I visit HKG on NW two to four times per year, I visit TYR two or three times per year on CO, I visit the East Coast probably two or three times per year usually on CO or DL, plus I visit Europe once or twice a year, usually on VS, KL or CO. Most of my "local" flights are on WN due to the greater flexibility and big planes into otherwise RJ destinations like RNO and SMF.