Abstract: The present invention features a Product Information System (PISYS) which presents advertising and product information to grocery shoppers. The system includes one or more shopping carts with a bar code scanner to read Universal Product Codes (UPCs) from merchandise. An artificial intelligence system presents advertising and general product information. The system determines the shopper's tastes from choices which the shopper expresses explicitly and from characterizations which it infers by examining the shopper's buying habits. When the shopping session is complete, the PISYS shopping cart transfers relevant information to a PISYS check-out counter, which transfers it directly to an in-house central computer. Because a PISYS shopping cart interacts with a shopper at the very moment he is making a purchase decision, it provides the most effective means for advertising.