Today, the media and communication markets are undergoing a fundamental transformation. This thesis focuses on the market for electronic media products in the higher education market and especially on the market for scientific journals. In contrast to other media sectors this partial market shows a significantly different structure and different characteristics. For around 10 years scientific publishers have offered electronic versions of their products, which is of vital importance for the scientific communication of research activities all over the world. Content providers as well as libraries face new duties and responsibilities. Librarians especially have to cope with the new assignments as advanced information intermediaries. In view of decreasing library budgets and increasing costs for scientific information sources, the economic responsibilities have become an important issue in librarians' daily work. Thus, one major goal of this research is to obtain a better understanding of the way in which scientific content is traded over markets.