I’ve tried to understand this for a while.
Qantas sells 80$ worth of value of frequent flyer points that ‘Coles’ in you example buy and passes on to their customer, for 100$ so there is an immediate 25% profit margin. And that’s before they hold onto the effective money, sell a seat that was probably vacant, tie you to the airline, on sell something else like car hire, sell wine at a profit. The list goes on and on and on.
All the while, not being burden with expensive assets such as aircraft.
A accountants dream. Until the primary brand gets damaged.