This book takes a practice approach to studying platform business models. Drawing from the growing academic literature as well as the practice world, this book intends to provide a framework for analysing platform business firms. Leveraging on the early literature on network economics (that was largely analytical) and the popular writing about new organizations, this book takes a strategic perspective. It answers the five big strategy questions about platform business firms: a. What are platform business models, and how are they different from others; b. How do platform business firms operate, and what value do they create? To whom and how; c. What are those resources that platforms possess and leverage to create and sustain their competitive advantage over others; d. Why and how are they successful? Why do they perform differently from others? What metrics of performance should we use to study and analyse their performance; e. Is this business model sustainable? What determines the longevity of such firms? What are the regulatory and social challenges that these platform business firms face? How do regulators and the larger society manage the disproportionate power distribution among such firms? The book is strategic in nature and highlights the resources defining the strategies of successful platform business firms. In doing so, it provides a field guide for entrepreneurs and managers embarking on building a platform, by providing a portfolio of decisions to make. Though the frameworks could be generalized, the book focuses on platform businesses, rather than societal platforms. With a few extensions, it is possible that these frameworks could be easily applied to non-profit and or social enterprises as well.