http://www.investopedia.com/articles/company-insights/092816/how-sustainable-whole-foods-competitive-advantage-wfm.asp
"Whole Foods' strong brand identity is likely its greatest source of competitive advantage. The company has established itself as the leader in the organic and natural food segment, and has invested heavily in store quality and customer service. These factors differentiate it from other grocers and they have fostered a relatively loyal customer base. To maintain this reputation, the company will have to continue ranking among the industry leaders in facility investment. It will also likely incur high labor expenses to keep customer service up to its high standard. These drags on earnings and cash flow are partially offset by increased pricing power."
Funny how everyone knows that the team members are one of the biggest advantages of whole foods except whole foods.