The lecture covers principles of Internet Economics from a theoretical and applied perspective. The first chapter focuses on the characteristics of digital goods and the digital network economy. Using examples of software and media industries, digital value chains, digital rights management and multi-channel management are explained. In the second chapter the main principles of the software industry are presented. After a brief market overview strategies and organizational aspects of the software industry are focused. Following the importance of partnerships and acquisitions in the software industry is discussed using different examples. The effects of the centralization on the software industry will be worked out in the chapter on software clusters. In the chapters on sales and pricing strategies the current state of research and their impact on the practice is explained. The opportunities and challenges resulting from the characteristics of the digital market are also presented. New trends, such as Software as a Service and Cloud Computing complete the lecture. The lecture will be supplemented by guest lectures.