"For profitability, growth is a double-edged sword. It always requires additional investment, and the prospects of earning more than the cost of capital depend on the position of the firm in its industry. For companies with competitive advantages that they can maintain even as the market gets bigger, growth is an unambiguous benefit. But when markets enlarge, they often allow competitors to achieve comparable economies of scale and thereby undermine a major barrier to entry. Unprotected by barriers, companies do not produce exceptional returns." -Bruce Greenwald and Judd Kahn, Competition Demystified: A Radically Simplified Approach to Business Strategy
