An Internet-based customer referral system enables individuals and other business entities (“associates”) to market products sold on a merchant web site in return for commissions. Following registration, the associate sets up a web site (or other information dissemination system) to distribute hypertextual catalog documents that include marketing information (product reviews, recommendations, etc.) about selected products of the merchant. In association with each such product, the catalog document includes a hypertextual “referral link” that allows a user/customer to access the merchant web site and purchase the product. When a customer selects a referral link, the customer's computer transmits unique IDs of the selected product and of the associate to the merchant's site, allowing the merchant to identify the product and the referring associate. If the customer subsequently purchases a product from the merchant's site, a commission is automatically credited to an account of the referring associate.