As we have come to expect from Harvard's Professor Chesbrough, Open Innovation is a wealth of insight and knowledge in how organizations can transform themselves by blending the best of their internal know-how and external sources of perspectives. Beginning with an interesting historical vantage point, Chesbrough introduces us to innovation structures as they have evolved at the beginning of the twentieth century, through the establishment of central research & development facilities and beyond. It was historian Alfred Chandler who first researched the economies of scale that resulted from the internal research & development facilities. As it points out in the book, `these R&D facilities were so successful in extracting more efficiency out of increased understanding that they created natural monopolies in many leading industries, or economies of scope'. But many erosion factors have weathered these fortresses of knowledge, and now Chesbrough maintains that innovations, however clever, are worth nothing until a viable business model is found to exploit them. The function of a business model, according to the author and colleague Richard Rosenbloom, is to: articulate the value proposition; identify a market segment; define the structure of the firm's value chain; estimate the cost structure and margin, describe the position of the firm within the value network and to formulate the competitive strategy of the offering. So invention is not enough. Organizations most follow the path to commercialization, but that route often means it must work collaboratively with many others. This approach has many ramifications on company structure and ways of working. It is hard for organizations (and their leaders) to work on having core-differentiated capabilities, while still being open with their value network. Therefore, this leads ManyWorlds to assume that those things, which are seen as true differentiators in mature companies, must move away from a specific product advantages and more toward process differentiating capabilities. While there is always a role for product innovators, the model they operate under is not usually scaleable, and companies often grow into either `economies of scale' or `economies of scope'. But finding and developing that all important part of the value network becomes a crucial skill in itself. Open Innovation is a truly excellent book that a review cannot do justice to. With detailed case studies on Xerox (and spin outs), Intel and examples from many other companies, Chesbrough has written an insightful and timely work that draws many threads together. Executives who want to explore how facets of innovation, whether internally or externally motivated, sourced or executed, would not find a better read than Open Innovation.