Service robots that coexist with humans in everyday life have become more common, and they have provided customer service in physical shops around the world in recent years. However, their potential in effective sales strategies has not been fully realized due to their low social presence. This study aims to clarify what kind of robot behavior enhances the social presence of service robots and how it affects human–robot interaction and purchasing behavior. We conducted two experiments with a sales robot, Pepper, at a retail shop in Kyoto. In Experiment 1, we showed that the robot’s social presence increased and that customers looked at the robot longer when the robot understood human gaze information and was capable of shared attention. In Experiment 2, we showed that the probability of customers picking up products increased when the robot suggested products based on the humans’ degree of attention from gaze and posture information. These results indicate that the robot’s ability to understand and make utterances about a customer’s orientation and attention effectively enhances human–robot communication and purchasing motivation.

Humanlike robots interact with people in daily situations, and various studies concerning such robots have been conducted. However, robots are easily ignored due to their lack of social presence, with their customer service behavior and sales strategies not working well in many situations. In this paper, we aim to improve the social presence of a sales robot by enabling shared attention with visitors. In an actual shop, we investigated whether a robot could improve its social presence by indicating that it could understand the gaze direction of visitors. We found that the robot's statements regarding the direction of the visitor's gaze information and the timing of such statements with the visitor's gaze change improved the robot's social presence, leading to an increase in the number of groups that looked at the robot for a longer period. This paper reveals that enabling shared attention between humans and robots can strengthen a robot's social presence and its ability to work effectively in a real-world environment.