NETWORK-BASED METHOD AND SYSTEM FOR TRANSMITTING DIGITAL DATA TO A CLIENT COMPUTER AND CHARGING ONLY FOR DATA THAT IS USED BY THE CLIENT COMPUTER USER

A flexible product distribution and payment system for computer network based electronic commerce is disclosed. Primary content data is made available to customers through a detachable local storage medium, such as a DVD or CD-ROM disc, or over a network connection. The primary content is capable of being accessed and played back through a computer or game console at the customer site. The primary content distribution may comprise a superset of content that is intended to be used by the customer. The customer is allowed to view and access the encoded primary content, and is charged only for the primary content that is used. Content that is encoded on the medium but that is not used by the customer remains on the medium but is not charged. A content database and customer database maintained at the primary customer site maintain records of products ordered and used by the customer, as well as identification and use patterns associated with the user. Authentication and use trigger data associated with the distributed content alert the primary content server computer when customer use has occurred and when a charge to the customer is appropriate.