A book about the commercial use of social media, is that still of any value in this online era? Since you can find almost anything online with a simple search query and a mouse click, what can a traditional book add to that? Indeed, information about the topics covered in this book is also widely available online. Nevertheless, especially in this era of rapid digital developments, a book provides structure and overview. It distinguishes the main topics from the side topics, without getting distracted by too much details. This book offers practical and readily applicable knowledge, necessary to get acquainted with social media in a commercial setting. In 9 comprehensible chapters, it presents an introduction to the main topics of this dynamic field of study, such as eWOM and reviews, online consumer behaviour, business models of social media, online engagement, big data, and social media planning. After reading and studying this book, you are thoroughly introduced in the commercial use of social media, you have familiarized yourself with its main aspects, and you are able to identify its key concepts. By means of many recent examples, the theory is directly applied to practical situations. And, in accordance with the spirit of Web 2.0 and crowdsourcing: if you have ideas or suggestions related to the subjects in this book, please inform the authors!