A video game machine with a portable memory module is used by a customer to generate and store a shopping list and other types of shopping related information. A retailer periodically transmits to the customer a CD-ROM storing merchandise information, coupons, and the like. The CD-ROM is run using the video game machine to generate a shopping list. The shopping list is stored in the memory module and removed from the game machine for taking during a shopping excursion. During checkout, coupons stored in the memory module are applied to a current purchase, and an electronic receipt is written to the memory module. If the customer has met a particular purchase amount, a software key may also be written to the memory module. The software key is used to activate a software program also delivered with the CD-ROM. Alternatively, the software program may be downloaded over the Internet using the video game machine, and the key to activate the software may be obtained via an automated teller machine that effectuates payment for the software.