the same time, adware also raises privacy concerns. We study the e¤ect of programmers’ choice between shareware and adware … the one hand and their loss of privacy on the other hand. We also examine the implications of improvements in the …

privacy, which results in the highest profit for the monopolist. In fact, all consumers are better off when opting out is … when opting out is prohibitively costly. We introduce the notion of a privacy gatekeeper --- a third party that is able to … act as a privacy conduit and set the cost of opting out. We prove that the privacy gatekeeper only charges the firm in …