"Although often treated as separate aspects of strategy, barriers to entry and competitive advantages are essentially alternative ways of describing the same thing. The only necessary qualification to this statement is that barriers to entry are identical to incumbent competitive advantages; whereas entrant competitive advantages—situations in which the latest firm to arrive in the market enjoys an edge (the benefit of the latest generation of technology, the hottest product design, no costs for maintaining legacy products or retired workers)—are of limited and transitory value." -Bruce Greenwald and Judd Kahn, Competition Demystified: A Radically Simplified Approach to Business Strategy
