MAY–JUNE 2018 INTERACTIONS 53 INTERACTIONS. ACM. ORG consequence, they seem generally more appealing, more valuable [1], and more persuasive [2]. Personalization makes use of these effects by reinforcing a sense of uniqueness through the interface. This sense of “me-ness” is appreciated by users [3]; moreover, they may benefit from information that is more relevant to them or from functionality that better suits their needs. However, personalization is often done implicitly by algorithms. Therefore, users might not understand why and how—or even might not be consciously aware that—something was adapted to them that may potentially infringe on their privacy.

To explore individual perceptions of privacy and personalization, we conducted interviews in Germany. Typical reactions to personalized content were Netflix recommendations rated positively and advertisements often seen negatively. The personalization of the Facebook news feed and Google search was met with both appreciation and skepticism. Even though most users enjoyed the benefits of personalization in certain contexts, they were left with some sense of unease. They also wondered where their identities were stored and traced on the Web when they could neither tell nor control what data was collected and how it was processed.