In 2021 Susanne Hensel-Börner of the HSBA Hamburg School of Business Administration and Udo Kords of the FOM published a study titled Duzen bringt keine Vorteile, saying du brings no advantage. In an experiment, 308 participants watched short videos of sales staff greeting customers in a bank, a car dealership and a sports shop. The staff used either Sie or du. The authors report: Kunden reagieren mehrheitlich positiver auf die Anrede mit Sie. Most customers respond more positively to being addressed with Sie. Taken across all three settings, the likelihood of buying that participants reported was significantly higher with Sie.