Originally Posted by irishguy28

Most likely having benefitted from a number of such offers in the (recent) past.

Discounts are only offered when the revenue management's software does its magic and comes up with limited scenarios in which they may decide to offer all/some a proactive discount upgrade.

If anyone is selected for a discount offer, you are pro-actively informed; you do not find this out only by asking.

Please look at the long-running thread following all such offers and ask any further upgrade-specific questions there:

New policy for paid and miles upgrades (AF/KL) - sept 2017