Abstract: A method for a media provider in a media-on-demand network to selectively insert media items into a media stream consists of determining a subscriber's preferences for inserted content, determining suitable positions in the transmitted stream for insertion of other media items, and inserting items into a stream being transmitted to a subscriber. The inserted items can be commercial advertisements from advertisers (170), or other items as selected by either the provider or subscriber, and can be interactive items of indeterminate duration. The media provider utilizes the subscriber's preferences to selectively insert media items into a media stream at the previously determined suitable positions. Advertisers (170) can monitor the delivery frequency of advertisements to subscribers and adjust the price of an ad to change the ad's delivery frequency. The media service provider maintains an ad queue for each user and can order ads in the queue based on the price of each ad.

Abstract: A system and method for dual key dual database access control and identification system (Dual Key System) and method to maintain security, organization and privacy during electronic transactions. A dual key access card system maintains two separate and distinct database (201, 202), a public file database (202) and a private file database (201), for a given access cardholder. Each access cardholder has a record in each maintained database (201, 202); however, the records can only be integrated through the use of two record identifiers stored on the holder's access card (100). The dual database system allows the data maintained in each database to be kept relatively small, and allows for the anonymous public data to be processed more efficiently without knowing the identity of the person whose information is being maintained. As a result, an affinity-modeling engine can constantly run against the anonymous data while maintaining cardholder security and anonymity.