Originally Posted by
mitchmu
Upgrades are fewer because of HODs, TODs, mileage redemption, SHARES failures, and internal shenanigans.
It does not need a new theory. It is simple.
I think that domestic upgrades are harder because of two main factors: (a) less capacity (including fewer F seats) and (b) SHARES selling upgrades before offering them for free with CPUs. With (b), as long as the up-pricing is determined reasonably, taking into account the relative costs of the coach and cheapest F fares, I can live with it. (I've hated the CPU idea from the start - much prefer the E500 and CR-1 approach!)
International upgrades seem to be relatively easy to get, for a 1K at least, as long as one is willing to pay a bit more than the minimum coach fare.