As well as collecting points for flights when you spend, the other way to get into the rarefied air of First, Business, or even Premium Economy is to get an upgrade.
These days, most airlines do offer passengers the option to bid for a last minute upgrade at a much cheaper price than they would have paid upfront – but paying to be upgraded will never beat the thrill of getting it for free.
However, with security tighter than ever and profit margins squeezed in recent years, getting a free upgrade is no easy task.
So, how can a keen traveller bag that move up a notch on the plane?
