Customized marketing, so called 1-to-1 marketing, is often viewed as the panacea of e-commerce. User profiles, such as click streams logging every site the user accesses, are exploited to generate a profile of interests of the users. Marketing measures like advertisements in form of banners or product presentation are tailored according to these profiles. This kind of customizing suffers from insufficient information about the current interests of the users: the profiles are only a collection of past actions of the users. Additionally, sometimes personalization is seen an invasion of privacy and often unsolicited advertisements unrelated to the users’ real interests are cited as an example of the nuisances of 1-to-1 marketing. This shows the dilemma that 1-to-1 marketing faces: The users feel they already offer too much information about themselves. Currently, users solve this dilemma by disabling all technical means that enable user profiling, e.g. by disabling cookies in their web...