This book illustrates the challenges that regulators and policy makers have faced in the transition from the ‘old’ network industries to the new digital ecosystem. It succinctly describes the evolution of digital economy, its main actors, notably global digital platforms, as well as its interactions, interdependences, and trade-offs. Eventually, it proposes insights about why public rules are needed, what kind of rules could be more effective, fair, and efficient, and who should pose and enforce them.  The book is opened by an introduction, dealing with Digital Transformation, Big Techs, and Public Policies, which provides a general conceptual and thematic framework to the following analysis but could be also read as a stand-alone paper. The following chapters are grouped in two parts:  I. The Evolution of Digital Markets and Digital Rights, and II. Regulating Big Tech’s Impact on Market and Society. The secondary title - the European approach – has a twofold meaning. It highlights the fact that this work has a clear focus on EU law and policy - although the economic and institutional issues addressed are global phenomena, common to all world’s economies. In addition, it also underlines that European digital policy is not yet complete and effective. This book intends to provide a small contribution to the ongoing policy making process, as well as to the wider academic and policy debate.