Client and server system for coordinating messaging between motivated buyers and listed sellers

An electronic transaction processing system for coordinating requests for products and/or services from at least one buyer to at least one seller, each of which operate a party client system to interface to the electronic transaction processing system, comprising:

• a database of records of standing requests, wherein standing requests include information regarding products and/or services requested by a buyer, wherein at least two of the standing requests have a product or service category associated with each such standing request, wherein the information stored for a categorized standing request comprises data fields defined by pre-defined parameters, and wherein the data fields for at least two different categories are two different sets of data fields, such that not all standing requests include the same data fields, but have data fields that depend on the standing request's category;
• logic implemented on hardware for receiving over a network a standing request from a buyer;
• logic implemented on hardware for determining whether a seller has agreed to pay to receive a matched standing request;
• logic implemented on hardware for matching the standing request from the buyer to a seller, and
• logic implemented on hardware for the matched seller to receive the matched standing request from the buyer when the matched seller has agreed to pay to receive a matched standing request.