NEW YORK (The Street) -- Spirit Airlines (SAVE - Get Report) , known for its "bare-bones" and "no-frills" air travel accommodations, delivered revenue and profits Tuesday that topped Wall Street expectations. With the company looking to expand its ultra-low fares to more destinations in the coming years, it could mean more profits to investors, given Spirit's margin-expansion capabilities.

Spirit's unique and disruptive low-cost business structure has paid off handsomely for shareholders. Its results Tuesday show that price-sensitive customers are getting the benefit, too, which bodes well for the long-term performance of the stock.

Helped by a 1.3% decline in fourth-quarter fuel costs, which makes up roughly 40% of Spirit's annual expenses, the Miramar, FL.-based company reported a fourth-quarter net income of $55.9 million, or 76 cents per share.

Aside from lower fuel costs, Spirit benefited from pre-tax margins that expanded in the quarter by 4.3 percentage points year over year. And for full year 2014, its adjusted pre-tax margin expanded to 19.2%, up 2.1 percentage points over last year. More than anything, it is the margin metric that shows how well Spirits business model has taken off.

Unlike other airlines that sell and promote in-flight accommodations customers may not need, Spirit is able to maintain high profit margins using what it calls a "Frill Control" model, which benefits customers because they are "never stuck paying for extras they didn't ask for."

Because of this, not only is Spirit able to offer cheap air fare, the company is then able to generate 40% of its revenue from add-ons like carry-on luggage and checked bags.

"During 2014, we improved our customers' understanding of our Bare Fare(TM) plus Frill Control(TM) product design, which led to increased customer satisfaction, improved our financial results, and maintained a very high completion rate while improving our on-time performance by 600 basis points," said CEO Ben Baldanza in a statement.

To his point, even though Spirit prides itself as a cheap airline company, it doesn't mean it offers cheap service. That its on-time performance improved 600 basis points, coupled with 17% jump in annual revenue indicates that customers can have the best of both worlds -- good service at a low cost.

 Excluding one-time items gains and costs, the company said it earned a profit of $58.7 million, up 43% year over year. On a per-share basis, that amounts to 80 cents, topping expectations by 3 cents.

Fourth-quarter revenue was $474.5 million, up 13% year over year, topping analysts estimates. Full-year revenue was reported as $1.93 billion, up 17% year over year.

In short, Spirit is a well-managed company that knows how to return value to shareholders by eliminating waste and operating efficiently. With its consensus buy rating and 26% premium implied by its average analyst price target of $96, this is a stock investors should want to own.

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This article is commentary by an independent contributor. At the time of publication, the author held no position in the stocks mentioned.