Southwest Airlines has run a profitable airline for more than three decades. Here are its secrets:Keep your profit-making assets working. Since an airplane can earn money only while it’s in the air, Southwest does all it can to keep its planes flying.Grow slowly and profitably. Southwest established its profitability as a regional carrier and expanded prudently.Stick with your unique selling proposition. People know that Southwest offers quality, low-cost travel. Despite its growth, Southwest has never tossed that formula aside.Invest in your people. After the World Trade Center attacks, other airlines were laying off thousands of employees. Southwest kept every one on the job.—Adapted from The Southwest Airlines Way: Using the Power of Relationships to Achieve High Performance, Jody Hoffer Gittell, McGraw-Hill.