Summarizing the extant research on marketing communications, social media and word of mouth, this book clarifies terms often incorrectly and interchangeably used by scholars and marketers and provides principles of effective marketing communications in social media for different brand types and in different geographic markets. Conversations among consumers on social media now have an unprecedented ability to shape attitudes toward people, products, services, brands and to influence buying decisions. Consequently, the digital era brings to the fore the importance of interpersonal relations and the power of personal recommendations. This book is the first to empirically investigate how the form and appeal of marketing communications in social networks influence electronic word of mouth, including an examination of brand type and geographic market. The author focuses on motivations and reveals why people exchange opinions about brands, products and services in the digital environment. The book summarizes the existing research on marketing communications, social media and word of mouth, provides a cutting-edge knowledge based on the analysis of the actual behavior of consumers and rules of effective marketing communications in social media. This research-based book is written for scholars and researchers within the fields of marketing and communication. It may also be of interest to a wider audience interested in understanding how to use social media to influence electronic word of mouth.