'Privacy, economics, and price discrimination on the Internet' by Andrew Odlyzko offers an economical explanation for the rapid erosion of privacy on the internet. Privacy appears to be declining largely in order to facilitate differential pricing. Privacy intrusions serve to provide the information that allows sellers to determine buyers' willingness to pay. The author predicts that the economic advantages of price discrimination are likely to remain in direct conflict with public dislike of such practices. There is no easy solution for this problem, and privacy erosion and differential pricing will continue to be contentious public issues.

Privacy, economics, and price discrimination on the Internet (27.07.2003)
http://www.dtc.umn.edu/~odlyzko/doc/privacy.economics.pdf