Those rates are a loss leader. It's a great strategy to get people in the seats and try to get add-ons like snacks, baggage fees, etc. In terms of an airline business model, the more budget the airline, the more of these rates you will see. The legacies really don't offer them because their pricing is typically all inclusive. These budget rates are also usually very restrictive. They are usually offered in the flying off seasons, at odd times, and to/from locations where traffic is light or a company is new to a market. It's a tactic that can work. But they of course are not exclusive to NK/F9. JB offers them, and of course so does SW. They are pretty common over at SW but with a big caveat that they are not really considered a loss leader because "bags fly free."

Bragging about a $19 rate isn't really a good idea. Unless a person adds on a bunch of other fees, that seat is being sold usually at a loss, but less of a loss than it would be if it were empty. The real concern for the ULCC model is that they are painted into the leisure travel corner. Business travelers are the ones with the money. They splurge on a lot since its typically not their money they are spending. We are seeing our bases in big cities being reduced simply because we cannot drive the same kind of traffic that a legacy, SW, or JB can. We are being moved slowly to leisure markets because this is where the ULCC model shines, but that is all we have. Any upset in that market and we go back to reducing our margins in profitability majorly.