words will never hurt me

An example of the pop-up warning in question.

Passenger Rights Group Says Delta Is Shaming Travelers Into Buying Ticket Upgrades

You might be familiar with the feeling: you go into a purchase with a plan of exactly what you want to buy. No frills, no fuss, no muss. But then, suddenly, you find you’re shelling out more money than you’d planned, perhaps after encountering some persuasive sales tactics. A passenger rights group says Delta Air Lines is employing shame as a method to get travelers to buy ticket upgrades they might not have wanted initially. [More]