Nowadays social network sites are present in all parts of our daily life. Nevertheless there are a lot of people who do not use them. What reasons do non-users have for their abstinence of social network sites? To answer this question six semi-structured interviews with German non-users were conducted. A qualitative analysis of the data shows that there are two main relevant aspects. Firstly, their general life situation, and secondly, different reasons for the abstinence of social network sites need to be considered. Two of these reasons which we identified have not been revealed in previous research. The concept of friendship and the communication style in social network sites as e.g. users who show a distorted presentation of themselves to show off were strong motives for abstinence.