Originally Posted by
Cymro
True, and this can be because a flight is empty - it's in their interest to get *some* extra revenue sometimes, but not to the extent that people can rely on paying less later on.
Absolutely agree.
If you see there is an upgrade, there's nothing stopping a lot of hungry upgraders with the same offer from diving in there and grabbing them.
A lot of companies have a policy of a given ceiling rate acceptable for an upgrade, if the flight has been bought by a third-party, so getting that price right will likely make a big difference too.
Worst thing ever, though, is upgrading from an aisle or window WT to a middle WT+ seat and paying for the "privilege".