You've asked a lot of questions, and which have very different answers. I'm willing to answer some, and assume that other FTers will address others. OK, here goes....
Originally Posted by
bniu
For an AA codeshare on JAL, ... Does AA pay JAL a set fee for each seat they sell?
The operating carrier pays the selling carrier a fee for providing/referring the passenger. Think of it this way, -- the operating carrier owns the plane and the seats. The codeshare carrier is just a selling agent. I don't know if it the fee is a set dollar amount (which I would guess to be unlikely) or a percentage of the revenue realized from that pax on that segment (which I think more likely).
Originally Posted by
bniu
Does AA keep all the gross revenue they sell on the flight?
The operating carrier gets all the revenue except what it pays the selling carrier.
Originally Posted by
bniu
So if AA completely sells out the flight,...?
Won't happen. The operating carrier only makes a certain number of seats in each cabin/fare category available for sale on a codeshare basis because it would rather sell the seats itself than pay the commission.