Provided is an information processing system including: a detection means for detecting a position of a customer, a product, or a carrier used for carrying the product; an acquisition means for acquiring identification information from the product; a determination means for determining whether or not a position detected by the detection means is a position that enables acquisition of the identification information; and a notification information generation means for, when it is determined that the position detected by the detection means is not a position that enables acquisition of the identification information, generating notification information used for providing a notification to the customer.