US 5,283,731 · Granted 1994-02-01

The 1994 Patent That Invented Automated Classified Ad Matching

Imagine a computer system that automatically matches people selling stuff with people looking to buy it — like a super-smart middleman. This patent describes how to create a database of ads, scan incoming listings for matches, and even call people with voice messages when something they want appears for sale.

Curated and verified by the IsItPatented Editorial team

The plain-English version

What it protects

The claim covers a computerized system for managing classified advertisements that automatically compares new listings against customer profiles (what buyers are looking for) and want ads (what sellers are offering). What's protected is both the database structure that stores ads and profiles, the comparison algorithm that finds matches between them, and the interactive voice response system that notifies users by phone when a match occurs. The patent also covers the reverse workflow: scanning new seller ads against existing want ads to alert interested buyers.

Why it matters

This patent captures the core logic of automated online classifieds at a time when the internet was barely public. It predates eBay, Craigslist, and modern job boards by years, protecting the fundamental idea of algorithmically connecting buyers and sellers without manual intermediation. The addition of voice notification was especially novel in 1992 — turning database matches into actual human contact at scale.

Real-world use

When you post a used car for sale on a classifieds site today and receive automated notifications because someone saved a search matching your listing, that matching logic descends directly from this patent's core concept.

Original USPTO abstract

A computerized classified ad system and method. The system comprises a data processor including means for creating an ad database comprising a plurality of ads, each ad containing text data describing an item to be made available through the system. In a first aspect, the data processor also includes means for receiving profile data describing an item sought from others through the system, and for comparing the profile data to the ads and for generating text output data when matches are found. An interactive voice response system converts the text output data into a voice message. In a second aspect, the data processor includes means for creating a want ad database comprising want ads that contain data describing items sought through the system and delivery data such as a buyer's phone number. When a new ad is placed in the ad database, it is also compared to the want ads. If a match is found, the system generates output data that includes the new ad and the delivery data for the matching want ad.

Patent details

Publication number: US 5,283,731
Filing date: 1992-12-23
Grant date: 1994-02-01
Assignee: Ec Corporation
Inventor(s): LALONDE; JAMES E., DETTMANN; TERRY R.
CPC class: H04M3/493

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