Money-back guarantees (MBGs) are becoming increasingly popular in corporate practice. However, successful implementation of this marketing tool requires a detailed understanding of the influence MBGs have on purchasing decisions. In this context, Matthias Vieth derives the effectiveness of MBGs based on various behavioral science theories. Through a comprehensive empirical study, it is shown that MBGs are fundamentally an effective tool for increasing purchase intention. However, various influencing factors must be considered, which the author systematically analyzes. The results are translated into concrete recommendations for the use of MBGs.