20. A computer network agent system according to claim 15 wherein the sell advertisement manager further comprises, in combination: an advertisement indexer for maintaining indexes for quick searching of the advertisements by product and vendor characteristics; an active advertisements function for maintaining information about advertisements that are currently active, wherein an active decision agent manager is notified as each new advertisement is accepted by the active advertisements function so that pending searches can be matched against the new advertisement; a future advertisements function for maintaining advertisements that have been submitted to the market, but are not yet active because their effective datetime has not yet been reached; an expired advertisements function for maintaining an archive of advertisements that have expired, for later analysis; an active decision agent manager for maintaining a list of all decision agents that are currently searching this market for products; and an expired decision agent manager for maintaining a list of decision agents that have completed their searches, whether successfully or not.
21. A computer network agent system according to claim 20 wherein the active decision agent manager comprises, in combination: an immediate agents function for keeping track of decision agents that are performing searches that are to be performed and results returned as soon as practical; a basic search engine for executing queries associated with each incoming decision agent by consulting active advertisements to match the query against all active advertisements; a pending agents function for keeping track of decision agents that are performing extended searches; an incremental search engine for matching each new advertisement against the queries of the pending decision agents; and a current demand search engine for matching demand queries of demand agents against the queries of decision agents that are residing in immediate agents or pending agents, to identify active decision agents that are searching for a certain product or product category.