Frequent flier miles may not be actual cash, but for many, jetsetters they’re just as good. Some airlines, though, may not be giving you all the miles you think you deserve.

A new PricewaterhouseCoopers study shows that if airlines switch to frequent flyer programs based on dollars spent rather than miles traveled, around 45% of passengers could lose out on points, USA Today reports. Meanwhile, around 40% of flyers would actually get more points, while 15% would see no change.

People who buy cheap tickets for long distances will lose points, while those who buy expensive, short flights will gain.

Several airlines, including Delta, have already made this change, while others are considering similar moves. Giving additional points to people who spend more money on tickets incentivizes that extra spending, helping airlines make bigger profits.

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