What these companies should be doing, instead, is to opt for a course based on an honest and unbiased assessment of their core businesses.

Zook writes that a rich adjacency expansion program can help a company avoid mistakes made by companies such as Gucci, which eroded its high-end brand and bottom line by expanding into lower-priced canvas goods sold through mass retailers.

Zook points out that when the company finally "pruned the new, unprofitable growth," it was able to return to its core and increase profits.

Unfortunately, since Profit from the Core was published in early 2001, Zook offers Enron as an example of an energy company that sustained growth through the ideas he presents.

Although Enron's shenanigans drove the company into bankruptcy by the end of the same year, the many other case studies Zook describes in his book offer an abundance of solid role models to follow when seeking growth strategies that work.—Review by Businessweek[5]