I beg to disagree - this is a way to lose revenue.

Take the example of Jaeger. On of the reasons that they are in trouble is that they had so many ways to buy their products at a discount that even total devotees would never dream of paying full price.

North American carriers use F and J as upgrade space and effectively fill from the top cabin down. Many have faced bankruptcy,

BA restricts premium cabins to those who pay for them. They do offer AUP and POUG, but these are promotional, designed to tempt you to regularly booking a higher cabin. If you take these offers too often, they cease to be offered.

Oh, and BA remains highly profitable when others are suffering set backs.