This study investigates the effectiveness of a humanoid service robot (HSR) versus a tablet service kiosk (TSK) along the stages of the point-of-sale (POS) conversion funnel. The observational data gathered by means of a field experiment show that the HSR elicited 26 times more interactions (i.e., passersby touching the screen) than the TSK and that these interactions lasted almost +50% as long. Moreover, more people looked at the store and consequently entered it when the HSR was deployed. Furthermore, more unique transactions were registered, and a higher amount was spent during the days when the HSR was present in front of the store. This study proves that implementing an HSR in the store environment is more effective than a TSK in attracting passersby and converting them into buyers.