Visualizations are commonly seen as one of the distinguishing features of service design; yet little research has been done on the topic. Building on questions raised by recent research (Segelstr√∂m & Holmlid; 2009) this paper analyses the results from 14 interviews with practicing service designers. The interviews focus on user research. The analysis is aimed at answering why service designers visualize their material. It is found that the various visualization tools all serve the purpose of communicating user data to different recipients. Additionally the results points towards that there is a set of basic techniques; such as customer journeys and personas; which are almost universally used; as well as a long tail of techniques only used by a few companies. Finally; it is found that service designers to a large extent let the nature of the user data decide the form of visualisation together with the intended audience of the visualization.