Clark loves discount airlines like Southwest, JetBlue, AirTran, Frontier and others. When they go into a market, airfares start dropping like flies.

In April, the consumer champ took an hourlong flight to a market that was only served by full-fare airlines. He had to pay $1,350 RT! Had he had access to a discounter, he would have paid at most a few hundred dollars for the same trip.

Little wonder then that discounters are the only ones making money right now. The full-fares, meanwhile, are reporting major losses of up to $250,000 billion each quarter.

How is it that the discounters can offer their services so much cheaper? Typically, they run a much simpler business. The full-fares fly up to 8 or 10 types of airplanes in their fleets. Discounters, however, will only fly one or two types of jets.

In addition, discounters put the focus on customers by offering deals instead of trying to come up with new ways to fee you to death like the full-fares.

Let's take a closer look at the fees. Discounters like Southwest and JetBlue charge you zero to check-in a bag. The full-fares generally charge $15-$25 for the first bag.

How about sending a minor unaccompanied on a flight? Most discounters will charge you $25-$50. The full-fares will run you $100.

When it comes to talking to a human over the phone, a discounter like Southwest lets you do that for free. Most of the full-fares, however, will charge you $20-$25 to pick up the phone.

And taking a pet on the airplane? The full-fares will charge up to $150. Southwest, however, charges zero dollars.

Visit Kayak.com for a full list of airline fees.