Abstract: A computer-implemented system for brokering transactions between sellers and a buyer of goods or services, including a database, a seller interface, and a buyer's interface. The database contains information, including multimedia information, descriptive of respective ones of the goods or services. The seller interface enables the sellers to interactively enter information, including multimedia information, into the database. The buyer's interface provides a knowledge-based interactive protocol, enabling the buyer to select and review the descriptive information from the database, and makes perceptible the multimedia information in response to an interactive buyer request.