Warren Buffett had this to say in a 1999 Fortune article that was written as the tech bubble was coming to an end:"The key to investing is not assessing how much an industry is going to affect society, or how much it will grow, but rather determining the competitive advantage of any given company and, above all, the durability of that advantage. The products or services that have wide, sustainable moats around them are the ones that deliver rewards to investors."In the article, Buffett also points out that many of the most"glamorous" businesses...