Abstract: A computer-implemented method of finding a complementary set of parties to begin a negotiation for a trade in an item comprising: creating respective user models, based upon one or more external market factors, to respectively predict behavior of one or more respective users with respect to participation in a transaction in the item; evaluating current external market conditions with respect to the item; based upon respective user models and results of the current external market evaluation, respectively predicting respective current conditions in which respective users are likely to participate in transactions in the item; identifying respective users with respective complementary current conditions; notifying at least one respective user of the existence of at least one other user predicted to currently be likely to be willing to participate in a transaction in the item on conditions that are complementary to conditions on which such at least one notified user is likely to be willing to participate in a tra

Abstract: A computer-implemented method of buying and selling items on an electronic marketplace comprising: providing computer readable media encoded with rules that define multiple tiers of an order for a prescribed quantity of an item; wherein a respective rule for a respective tier sets forth a respective bid or offer for the item that is applicable to the respective tier; wherein a respective rule for a respective tier identifies one or more participants eligible to receive a respective bid or offer applicable to the respective tier; and wherein respective rules define prioritization of respective tiers; providing the order over the network while implementing eligibility rules for the tiers so that respective bids or offers are accessible only to respective participants eligible to receive the respective bids or offers; receiving over the electronic marketplace one or more responsive bids or offers to one or more respective provided offers or bids; matching provided bids or offers with received offers or bids in a

Abstract: A client program executes in conjunction with a web browser on a user computer. The client program captures submitted form data from HTTP requests and presents the user with the option of resubmitting the form data to related web sites based upon information transmitted to the client program from a metadata server. A processing engine, located in the client program or on the metadata server, extracts the submitted data from an HTTP request and creates data resubmission blocks using the extracted data. The data resubmission blocks replace related forms on related web sites but incorporate the extracted data. Instructions based upon which the processing engine extracts the data and creates data resubmission blocks are stored on the metadata server. The data resubmission blocks are displayed to the user through the web browser and can be submitted by the user without the need to re-enter data, in order to resubmit the extracted data to the related web sites.