I have never flown Frontier, but got their credit card to get the bonus FF miles. Just booked a FF ticket DTW to STL and that appears to have gone through seamlessly, although I do have to connect both ways in Denver, which is their hub. However, I wanted to book a ticket on the same flight for my traveling companion and was shocked at the price. Delta charges a total of $228 while Frontier is $585 for the same ticket. Why would anyone fly Frontier at these prices and how do they stay in business?

I don't think one flight comparison is really a valid measurement system.

In my experience, sometimes they're cheaper and sometimes they're not.

I have checked before and each time they were way higher. I usually do a comparison on Orbitz and so far, haven't found a cheaper one. Although, as Abram said, there probably are some.

They have a big problem staying in business that is why they filed for bankruptcy a while back. Today they announced a merger with Midwest Airlines. I've flown Frontier twice LAX - DEN because of semi-emergency situations with my parent's health and each time was such an odd experience - they have a very "unique" clientele - that's the only way I can really put it. It was just a weird flying experience.

It was actually Republic Airlines that bought both Midwest and Frontier. Frontier was starting to make a profit after declaring bankruptcy under Chapter 11 in April of 2008. The idea that it has a "unique" clientle is absolutely inane.