.... We have some "voluntary upgrade forms" which include taking details of the credit card to take payment for the upgrade. One way for a short flight is £100. It can be up to £500 on some long flights for WTP. When I notice people trying to jump class I present them with the form. They usually decline and go back to their seats.
In flight upgrades?
Excellent, I must try that: do all airlines do it?
Just ask the purser?