Harry Potter is the short formula for extraordinary literary success. More than 140 million people worldwide have already read the first four volumes. Another three volumes are planned. The author Joanne K. Rowling has managed to turn the kids of the Nintendo- and Pokemon-generation into passionate book readers. In the course of the last five years, the books have not only become part of popular culture worldwide but have also caused scientific interest at universities. What are the reasons for this global Pottermania? And why does this little boy with his glasses and his broomstick appeal to adults and children of both sexes alike?
             In the following, we will first have a closer look at the book market in general as well as on the market for children's books. Then, we will summarize the development since the publication of the first Harry Potter book and describe its process of global expansion. Thereby, we will concentrate on the success in Germany, but also elaborate on the development in the USA and Japan. Afterward, we will discuss the success factors that explain the phenomenon, Harry Potter. The paper ends with a short conclusion and an outlook.
             For an evaluation of the global success of Harry Potter, some information on the book market, in general, is a good starting point. The book market is more than other markets in the media business a rather multinational market, i.e., it is bound to national boundaries or better to language barriers (there is a German-speaking market, an English-speaking market, etc.). However, in recent years the trend goes towards more convergence, and many books have become global bestsellers.
             Although a detailed description of the different national book markets would be interesting, we will focus primarily on the example of the German book market. Within the European Union, the German-speaking market is the most interesting one. This is among other factors due to the high number of total popula...