Increasing numbers of commercial enterprises in the German-speaking countries are switching from the traditional formal Sie address for customers to the more casual du address. This article reports on a part of an interdisciplinary empirical study evaluating the effect that the address pronoun used towards the customer has on the perception of the salesperson. Respondents were shown short videos of sales encounters and asked to indicate their perception of the salesperson in a guided questionnaire. The choice of either du or Sie as the address pronoun used by the salesperson in the videos did not make a substantial difference to the way the salesperson was perceived by the respondent group as a whole, but some significant differences appeared within sub-cohorts, which were determined by the gender, age group and education level of respondents, and by the industries in which the videos that the respondents watched were set. The overwhelming majority of the significant differences in the perceptions of the salesperson according to the address pronoun used shows that the salesperson using Sie is seen in a more positive light. This suggests that, somewhat surprisingly and counterintuitively, addressing customers with du does not have the general effect of improving the perception of the salesperson.