A product analysis system 800 includes a detection means 810, a classification means 820, and a specification means 830. The detection means 810 detects an area of change in a product shelf from a video of the product shelf. The classification means 820 classifies the change in the product shelf in the detected area of change. The specification means 830 specifies the frequency at which a customer was interested in but did not purchase a product on the basis of the classification of the change.