Anyone would agree that this book is the best overview of competitive strategy analysis ever written. The strength of the book is a solid outline of subjects and questions to improve your thinking, and get to be a step ahead of the competition. In highly-competitive, commodity businesses, that's usually what strategies focus on.On the other hand, the rapid advances of knowledge and technology mean that the relevant benchmark is perfection, not the competitor, in defining an ideal best practice. In that world, this book has serious limitations, because the competitive dimension is often less important than the customer and user dimension these days.
Any business arena begins, as Peter Drucker so aptly put it, with the task "to create a customer." That reminder is especially relevant today when they are so many new ways to serve a customer's needs that no one has ever considered before. The strategic point of 'Blown to Bits' for example is that almost every business will see its vertical value chain (moving from resources through to the customer) broken apart into tiny segments each served by specialists. If you did not begin with that perspective in analyzing the impact of electronically-based business practices, you could easily focus on the wrong tasks using this book to create an over-broad strategy focus, rather than concentrating on just a few areas.
I suspect that the applications of Moore's Law and Metcalfe's Law need to be explicitly considered as part of the analysis that Professor Porter is recommending.
A more general weakness in this book is that it assumes that future conditions will be stable enough to draw conclusions about which conditions will be favorable, without giving enough guidance on how to deal with the increasing frequencies and degrees of volatility that we see (in areas like financial markets, commodity prices, the weather, changing customer preferences, and so forth).
Although no book that takes such a narrow focus can help but have weaknesses (like having the podiatrist not notice that you have kidney problems), if you want a good start of how to think about competitors, this is the book for you. Just be sure you keep developing yours strategy with additional dimensions after you finish using this analysis.
If you have read none of Professor Porter's works, this is the one book you should read.
