The complete thesis consists of a literature review on the relevant themes of this thesis and two case studies. The structure of the thesis is the following. The first chapter after this introductory chapter is the literature review, Chapter 2. It describes literature on digital products, mass customization and variety. Chapter 2 ends with a confrontation of the literature and the overall research question, and poses four hypotheses which are the foundation for the case studies. Chapter 3 contains the research methodology. In this chapter I discuss the research strategy, the research design with the unit of analysis, site selection criteria, I describe the data sources that where used, how the data was collected, how the data was analyzed and the instrumentation. Chapter 4 contains the case studies on Last.fm and Pandora Media, where the collected case study data is analyzed and reported. Last.fm and Pandora Media are both Internet based companies that offer the listener to customize and personalize their listening experience, and discover new music. They both follow different strategies to accomplish this. Both case studies are analyzed and reported in the same manner and in the same structure. The main data sources are three interviews. The thesis ends with Chapter 5, where the results are discussed and conclusions in perspective to the overall research question are drawn. Also further research is suggested in Chapter 5.