This is the first book length study of the emergence of an important new form of expertise - industry analysts - whose outputs exercise enormous influence over the Information Technology market. Industry analysts are in the business of shaping the technological and economic future. They attempt to 'predict' what will become the next big thing; to spot new emerging trends and paradigms; to decide which hi-tech products will win out over others and to figure out which technology vendors can deliver on their promises. In just a few short years, they have developed a surprising degree of authority over technological innovation. Yet we know very little, if anything about them. This book seeks to explain how this was achieved and on what this authority rests. Who are the experts who increasingly command the attention of vendor and user communities? What is the nature of this new form of technical and business knowledge? How Industry Analysts Shape the Digital Future offers the first book length study into this rarely scrutinized form of business expertise. Contributions to this volume show how, from a small group of mainly North American players which arose in the 1970s, Gartner Inc. has emerged as clear leader of a $6 billion industry that involves several hundred firms worldwide. Through interviews and observation of Gartner Inc. and other industry analyst firms, the book explores how these firms create their predictions, market classifications and rankings, as well as with how these outputs are assessed and consumed. The book asks why many social scientists have ignored the proliferation of these new forms of management and technical expertise. In some cases scholars have 'deflated' this kind of business acumen, portraying it as arbitrary knowledge whose methods and content do not deserve enquiry. The valuable exception here has been the path-breaking work on the 'performativity' of economic, financial or accounting knowledge. Drawing upon recent performativity arguments, the book argues the case for a Sociology of Business Knowledge.