This document described the many factors that influence the level and type of competition in an industry. Most of its descriptive analysis was intuitive and thus helpful to read systematically. However I had one concern. A basic premise of economics is that suppliers do not compete with buyers and that customers do not compete with firms. Rather, customers compete with other customers, firms with other firms, etc. This document stated, several times, that customers competed with firms for better prices, etc. This is a misunderstanding of what competition is, a misunderstanding that concludes in understanding economics as a "zero-sum" game, where every win is accompanied by loss for another player. While I doubt the author of this piece would agree with this conclusion, its important to recognize proper economics. A better word to describe the phenomenon the author discusses is "interaction." An industry's structure and the competition a firm experiences are affected by a wide variety of interactions between competitors and non-competitors alike.