Web 2.0 services have experienced a very strong growth in the last 4 years, and now account for a large part of the global internet audience. The development of these services comes with a deep transformation in Web uses which may prefigure the future of media in an ultrabroadband world. The...

Two factors play a decisive role in the structuring of Internet based markets for infomediation (informational intermediation) : network externalities and information processing. First, these are examined separately. The two-sided markets literature focuses on the impact of network externalities...