I find the information on Richard Galanti, CFO of Costco, to be particularly poignant of the culture and success of Costco. "We try to be forthright and deal with the issues head-on, focus on the long-term, and not over promise."
Now if any business should be fearful of Amazon, I would say a likely candidate would be Staples. Why? The stuff they sell is standardized commodity types of products. You don't need to go to the store to tangibly touch a twenty four box of pens that you buy regularly!