Those other companies do too So it's not distorting the competition IMO. If none of them had kickbacks then the prices would be overall higher but people would still fly because most of us don't just fly for the hell of it but because we have places to go.
replyNobody claimed it was distorting the competition.
replyI pointed out the simple fact that Ryanair can't be considered a counterexample to airlines tending not to make money on flights since it relies on upsells to make a profit.