The economic value of user contributions to Internet sites: Andy Oram
Useful starting point where the author points out that many Internet businesses have huge valuations with only small amounts of physical assets on their balance sheet.
“The phenomenon of building a business on user-provided data is not completely new (for instance, a colleague reminded me that Zagat’s has done it for years), but the Web, and particularly Web 2.0, makes it a significant factor in the economy.
The economic aspects of aggregating user-provided content has been noticed; in fact, it has been criticized as a “concentration of the economic rewards into the hands of the few.””