The REAL answer is that it is a good way to avoid taxes. Government taxes are on base fares for air tickets. The airlines have done a good job of charging fees for 'extras' that were otherwise free before. For example, 15 years ago a ticket price included bags. But today, taxes are still very high, and airline tickets are taxed worse than cigarettes. One way to fight it, is to do what one can to remove items from the base ticket and sell it as an extra. Bags, food, etc.

Remember, the base fare is what is taxed like crazy. Bag fees, food fees, the airlines get to coin that without the crazy taxes that they have to pay on the base fare.

THAT is the reason Spirit is doing what it is doing. Base fare prices are very low, and that is what is taxed. It's a smart business move. Other airlines do it too, but not the same extent. It's still a smart move. The next question is, how long before the government decides to go after the extra fees for revenue (tax them like base fares). That's something I could see Obama doing, especially if the aviation user fees fails. Will the ATA (or A4A?) lobby be strong enough to beat the socialistic Obama CHOO CHOO going down the tracks? That remains to be seen.