1. A product purchasing method comprising: at a point-of-sale self-checkout terminal comprising a code reader device for automated entry of a product identification code present on items for purchase and a customer input device for receipt of data from a customer, receiving from a self-checkout customer a first input at the customer input device initiating a purchase of an item that does not have a product identification code compatible with the reader device present on the item; querying a database to identify a first plurality of items based on a prediction of purchase of the items; in response to the first input, displaying to the customer a graphical user interface comprising a first plurality of user-selectable icons each of said icons representing one of the first plurality of items; receiving from the user a second input selecting one of the first plurality of icons; and processing a purchase transaction for an item corresponding to the selected icon.