The book is, loosely speaking, about big data and its various possible and actual uses in different walks of life, especially in business. Data-ism basically refers to the all-pervasive importance of data especially in the future -- to the tune of "data is the new oil".
The book quite welcomely also includes ethical discussions, especially towards the end of the book, about how much data about our activities in, say, in the Internet can reveal about our preferences - including such preferences which we are unaware ourselves.
The book is quite heavily built around case studies, which for the most part travel with the author throughout the book, from theme to theme. In addition to the case studies, the book also includes general discussion and technology description, but it most often is motivated by an opening case.
Was it good?
The book has its merits and its drawbacks. On the plus side, the book is quite accessible and well-balanced overview of how data can be put into use in different walks of life, and what potential problems this brings about or has brought about. The case studies are also quite interesting and serve a clear purpose.
However, I increasingly like the "make it vivid" style of writing in general audience non-fiction books. In this book, for example, the descriptions of the outer appearances of featured people is striking to a degree of being annoying. Who cares, what is the texture of someone's moustache and how it plays along with the colour of his tie, if one wants to read about predicting customer behavior with social media data.
The main take-away for me?
The main take-away perhaps once again is the increased appreciation of what can be done with data, and how many applications there are for data accumulation, processing and consequent decision-making.
Who should read the book?
The book on Amazon.com: Data-ism