Spirit Airlines posts consistent profitability despite rapid-fire new route introductions

Spirit Airlines' rapid growth during the last couple of years has not compromised the carrier's profitability. During a time when it is not uncommon for the carrier to introduce 20 new route pairs during a half-year period, Spirit has maintained and grown its profits while undergoing a fundamental shift in its business.

As it continues to turn its attention to the US domestic market, Spirit seems unfazed by JetBlue's moves into some of Spirit's Latin American markets, as JetBlue by YE2013 will compete with Spirit on all its markets from Fort Lauderdale to Latin America. But Spirit's US domestic growth remains unabated, and will account for the bulk of the roughly 22% capacity increase Spirit plans during 2013.

Spirit also declares that it has one of the most enviable cash positions in the industry, which at YE2012 was nearly 32% of the last trailing 12 months revenue. But the carrier's relatively young status in some ways diminishes the prospect of cash dispersion or other shareholder reward, as Spirit continues work to prove its business model has staying power.

It will be interesting to see how long it is before other airlines feel the need to head off Spirit's growth.