This book presents the theory of two-sided markets and its application to media markets for the first time, both intuitively and theoretically. Following a discussion of the economic fundamentals, relevant models of two-sided media platforms and their applications for competition policy are examined. Subsequently, the economic policy implications of the theory are presented. Using real competition cases in internet, newspaper, and magazine markets, the discussion focuses on whether and to what extent media platforms require different treatment under competition policy and law. Thus, the book serves both students of economics and competition law in understanding modern media economics. It also provides insights for the competition policy analysis of media markets in practical cases.