Of course they do. Why do you think they get money in return? You don't think that's linked to performance? They just put their name on a card, get a fixed amount of monthly money, and that's enough to let them lead at a loss on airline tickets?

Hacker News has become simple minded. It's embarassing.

Missed this so coming in very late, but wow this is unbelievably off the mark. The airlines do not operate a credit card company, full stop. They sell airline miles, at a fixed rate per mile, to the credit card companies. That’s it. Citi, Chase, CapitalOne, etc. are the ones that operate the credit cards.