When it comes to domestic airline frequent flyer programs, it’s hard to argue with the value presented by United’s MileagePlus program.

Taking no-frills, short distance flights on low cost carriers is a great way to fill in the hole on an open jaw award and to hop around Europe if you're traveling light.

You often cannot redeem traditional miles on these kinds of flights--or if you can it just wouldn't be worth it because the value you'd be getting per mile would be so low.