A commodity data processing system comprising: a reader configured to read an ID of a customer; a behavior tracking device comprising a camera configured to acquire images of the customer in a store and a plurality of sensors; a cart confirmation device, and a display configured to display information about commodities; wherein the plurality of sensors is installed on commodity shelves in the store and configured to detect movement of commodities displayed on the shelves, the behavior tracking device further comprises a processor configured to: identify the customer with the ID read by the reader when the customer enters the store; track movement of the customer in the store based on the images acquired by the camera and identify one or more commodities taken by the customer in the store; identify each commodity in response to a signal transmitted from one of the sensors that has detected the movement of the commodity; acquire commodity data of each of the identified commodities; after the customer has left the store, perform a settlement process for the commodities based on the acquired commodity data; detect that the customer faces the display; and upon detecting that the customer faces the display, generate and transmit to the cart confirmation device a cart confirmation command including a terminal code for specifying the display and the ID of the customer; and the cart confirmation device is configured to, upon receiving the cart confirmation command from the behavior tracking device, control the display to display a list of the commodities before the customer leaves the store, the list including a name of each commodity and a cancellation button for cancelling the commodity. a reader configured to read an ID of a customer; a behavior tracking device comprising a camera configured to acquire images of the customer in a store and a plurality of sensors; a cart confirmation device, and a display configured to display information about commodities; wherein the plurality of sensors is installed on commodity shelves in the store and configured to detect movement of commodities displayed on the shelves, the behavior tracking device further comprises a processor configured to: identify the customer with the ID read by the reader when the customer enters the store; track movement of the customer in the store based on the images acquired by the camera and identify one or more commodities taken by the customer in the store; identify each commodity in response to a signal transmitted from one of the sensors that has detected the movement of the commodity; acquire commodity data of each of the identified commodities; after the customer has left the store, perform a settlement process for the commodities based on the acquired commodity data; detect that the customer faces the display; and upon detecting that the customer faces the display, generate and transmit to the cart confirmation device a cart confirmation command including a terminal code for specifying the display and the ID of the customer; and identify the customer with the ID read by the reader when the customer enters the store; track movement of the customer in the store based on the images acquired by the camera and identify one or more commodities taken by the customer in the store; identify each commodity in response to a signal transmitted from one of the sensors that has detected the movement of the commodity; acquire commodity data of each of the identified commodities; after the customer has left the store, perform a settlement process for the commodities based on the acquired commodity data; detect that the customer faces the display; and upon detecting that the customer faces the display, generate and transmit to the cart confirmation device a cart confirmation command including a terminal code for specifying the display and the ID of the customer; and the cart confirmation device is configured to, upon receiving the cart confirmation command from the behavior tracking device, control the display to display a list of the commodities before the customer leaves the store, the list including a name of each commodity and a cancellation button for cancelling the commodity.