I believe one of the most important and general conclusions I reached reading partially Media Economics and The Wealth of Networks, and The Long Tail is that the changes brought by Internet are not superficial, but economically very profound. The new information technologies are moving market structures to another direction, after decades being anchored in the same model.
I found the explanation of four different market structures in chapter seven of Media Economics interesting: perfect competition, monopolistic competition, oligopoly, and monopoly. This order is from the most to the least competitive markets. The digital revolution, studied in the three books, is causing a decrease in market share concentration in some economic sectors, especially those related to information. If media markets are becoming more competitive, media conglomerates are becoming less powerful.
On another topic, I found an article published by The Economist regarding Anderson’s long tail and citations in academic papers. It summarized research concluding that as more as journals become available online fewer articles are being cited in the reference lists of the papers.