Many people who have been burned by going into new areas will grade this as five-stars for encouraging caution in expanding a company's scope. If that's all you want from a book, this is a five-star book. If you want to learn what the exact lesson is, and why that lesson is true, you'll have to look elsewhere however. If you want to learn how to beat the odds in this area, you will also have to look elsewhere.
I found Profit from the Core to be a directionless mishmash of data without firm definitions that repeatedly espoused the idea of "stick to your knitting." As a result, I took up Beyond the Core with great trepidation. At first blush, Beyond the Core seemed to cure some of the peripheral problems of Profit from the Core . . . until I began to notice how almost all of the important examples of continuing business model innovation had been excluded that seemed to fit all of the criteria (except perhaps being willing to be interviewed by the author). Mr. Zook continues to avoid defining what "the core" is, so that basic problem continues.
The book's message is "stick to your knitting . . . unless you have not choice . . . then don't go away from your cost advantages and knowledge." If you want to know a little more about that message, you can read all of the key points in the book summarized in the Afterword on pages 189-192 in less than five minutes.
The book will mainly be helpful to those who are thinking about making unrelated acquisitions. The advice: Don't do it! The odds are way against you . . . but even the most unrelated acquisitions sometimes work (GE bought NBC and has done well with it, for example). The book lacks clear direction for how some overcome the odds.
The book was also curiously silent about how companies can use small experiments to test their way into new areas. That's the way that most firms expand beyond their core.
The methodology looks very much like those employed in Build to Last and Good to Great . . . but don't believe it. Cases were selected in part based on whether Mr. Zook could interview the companies. So it's really a subjective sample. So take the conclusions with a selective grain of salt. Here are some of the cases of those who have prospered with expanding into new areas that seem to fit the Zook criteria but don't appear in the book: Beckman Coulter; Berkshire Hathaway; Clear Channel Communications; Education Management; GE; Iron Mountain; Nucor; Paychex; Sony; Virgin Group; Xilinx; and Zebra Technologies. It's not surprising that the book fails to describe the discipline of continual business model improvement as a best practice . . . a serious omission for this subject.
Ultimately, I think the flaw behind the book is to look at moving "beyond the core" separately from looking "at the core." If the two books had been combined into one that looked at how to outperform the competition, there would have been the basis of helpful insights. Or, this book could have been scoped down into how to grow into new areas with internal development activities versus acquisitions. That would have been helpful. But with the focus of "beyond the core," you are left in a never-never land that you may not want to be in. The other interesting question that could have been addressed is how companies prospered by eliminating the old core and replacing it with a new one through acquisition as a number of companies have.
As I thought about why the author might have chosen this direction, I realized that it may be an unconscious use of the older ways of strategic thinking. Those analytical schemes separated thinking about existing business areas from entering new ones. For some time though, most strategic thinkers have emphasized seeing the questions as connected. You should, for example, be pursuing your best opportunities. That means comparing all choices in some manner at the same time.
The other problem with data-heavy studies like this one is that you are relying on backward impressions (with 20-20 hindsight). Studies of best practices are best done by looking at the decisions and actions when they are made . . . and then measuring the results to see what happens. Interviews taken at such times reveal much different information than the neat success stories spun after the fact. Clayton Christensen does a good job of explaining this issue in chapter one of his new book, The Innovator's Solution.
As I finished the book, I began to think about the many unsuccessful unrelated acquisitions that I have run into among companies. In almost every case, I remember reading a thick book by a name consulting firm that had explained at the time of the purchase why the acquisition could not miss. Perhaps a follow on for this book would be how to avoid bad advice in evaluating acquisitions.