An information processing apparatus (2000) analyzes a captured image (12) generated by a camera (10) to determine a motion of a person. The camera (10) is a camera that images a display place where an item is displayed. The information processing apparatus (2000) detects a reference position (24) from the captured image (12). The reference position (24) indicates a position of a hand of the person. The information processing apparatus (2000) decides an analysis target region (30) to be analyzed in the captured image (12) using the reference position (24). The information processing apparatus (2000) analyzes the analysis target region (30) to determine the motion of the person.