Industrial organization economists have generally treated the firms operating within industries as fairly homogeneous. The firms are assumed to be similar in terms of the main decision variables so that there are few differences in the price: output, and product strategies preferred by each firm. Furthermore, the firms are believed to enjoy similar market power so that market power is essentially a shared asset. Some of the recent literature rejects the shared asset view of market power. Among the more significant contributions to this literature is the concept of strategic groups. This paper focuses on the relevance of the strategic group concept for entry theory.