A method and system is disclosed for searching and submitting intellectual property listings, goods and services offered for sale online. Tailored searching is provided in a convenient and efficient manner on the Internet via an Aggregation Portal. The Aggregation Portal provides a uniform and user-friendly interface, whereby intermediary services are provided to facilitate transactions utilizing the Internet. Such services include legal, valuation, insurance, escrow, brokering, consulting and other professional services. Further, a multiple-listing type of commission sharing is created between the Aggregation Portal and various Internet auctions and exchanges. In one embodiment, a software application is downloaded on a user's personal computer (or network terminal) for searching, marketing and transacting goods and services, especially intellectual property.