The Internet economy is characterized by the pervasive dominance of digital monopolies such as Alphabet, Amazon, and Meta, which have significant market power. Common explanations for the rise of these monopolies include external network effects, economies of scale, technological barriers to entry, user lock-in, and inadequate antitrust regulation. While these explanations may accurately describe the current situation, they are insufficient to fully explain the emergence of digital monopolies. This article presents an alternative historical-institutional perspective, arguing that the specific history of the Internet and the initial reluctance of Internet users to pay for services fundamentally shaped market conditions and made network externalities a central factor. From a historical-institutional perspective, it becomes clear that the specific course of change - including the multi-sidedness of digital platforms and the increasing decoupling of use and exchange values - is largely due to these initial market exchange conditions.