Abstract: A mobile device scans a machine-readable code on a collection container; a Web page is downloaded to the device from a Web application which generates or retrieves a unique identifier for the device. The device then scans a can and the can's unique identifier is transmitted to the Web application to determine if the can had been scanned. If not, the device is alerted and a credit for the device's unique identifier is updated in a database. Or, the device scans a card to obtain a user unique identifier and then scans the can. The device scans a machine-readable code of the collection container to obtain a unique identifier for that collection container. Or, a user scans the card using an embedded scanning device of a collection container before scanning a can. The embedded device includes the unique identifier of the collection container which is sent to the Web application.