The company also generates the best profit margins of any supermarket operator, he explained. Gross profits were a healthy 34.3% of sales in the most recent fiscal year, despite the top-line pressures of the weak economy.

Whole Foods' superior performance relative to its peers can be attributed in part to its product mix, a combination of not only natural and organic merchandise, but also high-end perishables and prepared foods.

“What impresses me when you go into their stores is the emphasis on quality,” said Chuck Cerankosky, an analyst with North Coast Research, Cleveland. “The merchandising is all about quality and unique foods on top of the natural and organic attributes.”

That is especially true in the prepared-food areas, he pointed out. Store-made food dishes such as gourmet pizzas, salads and ethnic entrees, often attractively merchandised on a network of hot and cold buffets, account for 19.1% of the Whole Foods' sales.

“One of the things he taught the industry to do was to upgrade their prepared foods,” Cerankosky explained. “Whole Foods not only used natural and organic ingredients in their prepared foods, but raised the quality level tremendously. They proved that consumers would pay up for better quality, and you have seen that same philosophy move into many other stores.”

Whole Foods seeks out locations with high concentrations of college graduates, citing well-educated consumers as among the chain's best customers.

Each store opening has become an event, with some of the massive locations measuring up to 10 times larger than the company's first store and including amenities such as full-service restaurants and cooking schools.

The company expanded beyond North America — something no conventional U.S. supermarket chains have tried in years — with the 2004 acquisition of the Fresh & Wild natural-foods chain in the U.K.

Throughout the banner's rapid rise, Mackey has remained a forceful personality with outspoken, sometimes controversial views. He advocates an approach to business called “conscious capitalism,” which seeks to elevate the concept of business as a social good.

He insists that companies can be both profitable and serve a diverse array of stakeholders, including investors, employees, vendors, customers and the environment.

“The philosophy I had before starting Whole Foods was that business is evil and government's good,” he told Reason.tv. “Then I started a business, and was trying to meet payroll, and I realized a lot of people thought I was the bad guy, so I had to kind of throw out my world view.”

Now, he said, after poring over the economic philosophies of such writers as Ludwig von Mises, Friedrich Hayek, John Stuart Mills and Adam Smith, he has come to believe in “markets, individual empowerment and individual choice.”

That libertarian-style view- point has often put him at political odds with some customers, who may embrace Whole Foods for its more left-leaning, “green” image.

His antipathy toward unions — he is famously quoted as comparing them to herpes — is one example of his outspoken nature, and this past year his comments about health care reform led to an online movement to boycott the chain.