Harnish covers some good points for smaller businesses and entrepreneurs but I honestly don't think he did much research on John D. Rockefeller, his methods and the Standard Oil corporation. I gained MUCH more insight into Rockefeller by reading the superbly researched and detailed biography of Rockefeller, "Titan", than I did reading Harnish's book. Harnish actually spends more time discussing case studies of medium to small business than he does on Rockefeller. The cynical view of Harnish is that he and the publishing company used Rockefeller's name and legend to sell the book, while actually providing little insight into the Rockefeller business system. In this instance, I'm inclined to cynicism.
This is a good book for entrepreneurs, not for understanding Rockefeller, his genius or his habits. I would not recommend this to someone interested in learning more about the business system and principles of Rockefeller.