The long-term success of Southwest Airlines is phenomenal. Whilst many airlines have come and gone over the years, Southwest has managed to make a profit for 45 years in a row (see this article for more details).
Thank you to Marc Binkley for helping with the background research to this example.
The Southwest success story is a good reminder that strategy is as much about what your business is NOT going to do as much as what it is going to do. This idea is reflected in the Value Disciplines framework. The model assumes that in any competitive market, no brand can excel in all areas, and it is better to focus on excelling in one (whilst being at least acceptable in the others). Southwest excels in operational efficiency which allows it to sell at low prices and still make a profit.