2. No position will remain unique forever. Aggressive competitors not only imitate attractive positions, they create new ones, and these can pose a much greater threat. Over time, these new positions can grow to challenge the attractiveness of the dominant positions of the day. (Consider the success of Komatsu over Caterpillar and of Nucor over U.S. Steel.)
3. Because no position remains unique forever, established competitors must continually strive to discover new strategic positions in their business. If they don't do it, somebody else will. (Consider Canon and Xerox.)
4. Unfortunately, most established competitors are not good at seeking, let alone actually discovering, such new positions. Even though their success today can be traced back to an earlier decision to create a unique strategic position for themselves, they now expend little energy on such efforts. Instead, they spend most of their time trying to improve the position they already have.
5. The bottom line: Improving one's current position is not enough. A company that succeeded by creating a unique position for itself twenty or thirty years ago must do that again and again if it is to succeed into the future.