Leibowitz and Margolis set out to debunk one theory: the "network effect", whereby better products are kept from success because everyone is using a dominant but inferior one. But, the authors are economics professors, so they set about this with meticulous citiations from references, which means this book is not terribly light in tone. Also they spend some time complaining that not enough people follow their academic work and knocking alternative positions. However, the utter destruction in the first few chapters of popular myths about QUERTY and Betamax makes for entertaining reading. Turning to the book's main topic, the software market, the authors look at various points in time and functionality where Microsoft is not dominant, and what happened next in each case. I do not feel that they give sufficient weight to the effects of fear and branding in this marketplace, but, in line with their central thesis, they do show that Microsoft don't always win through dominance. (Think Money vs Quicken where they didn't win, or Excel versus Lotus, where they beat an incredibly dominant competitor, and also won on a non-Microsoft platform (Mac)). The choice of magazine review results as the objective judge of quality is questionable, since reviewers can be swayed by hype, fear, marketing, etc., just like customers, but I think on balance this must be the best source of independent data that anyone has to work with. If you start off as a Microsoft-hater, I think you will hate this book too, as an example of establishment lies and distortion. If you admire Microsoft or are neutral, then the data presented will surely make the case.