This study explores mobile users’ perceptions about SMS advertising. The empirical study uses a double methodology. First, a qualitative study using the Q-method is conducted. Qualitative analysis reveals that negative attitudes are commonly shared, and that ad-clutter is perceived critically. Therefore, in a second step, a quantitative study is adopted to assess the impact of attitudes towards SMS advertising and perceived ad-clutter on reading behaviour. The main test is conducted over a representative sample of 302 mobile owners. From a behavioural standpoint, the results show ambivalent behaviour in most cases. In particular, the role of perceived ad-clutter is ascertained. Implications for practice and directions for future research are discussed.