Originally Posted by
thiosk
Oh so it's better to have the same fare throughout the whole flight? Why is it not good, does it affect the miles you get negatively? I noticed that I got super low mileage ten days ago when I came back from MSP. Like 2.200 miles all the way from MSP - CDG - ATH
Often it's cheaper. Two different fare classes means that you are buying two separate tickets that are put together on the same PNR. It can be much cheaper to buy just one ticket, even if doing so means that you must use a somewhat higher fare class for at least part of the trip.