An online media/prospective buyer tracking system that allows a seller or auctioneer of real estate to analyze the cost of advertising used to bring prospective buyers to an auction website wherein media codes embedded in the advertising references correspond to individual online web pages capable of recognizing the source of the advertisement that directs each potential buyer to each respective web page. The system recognizes the media code corresponding to an advertisement and assigns a portion of the cost of the advertisement to each site visitor, making calculations regarding the cost per visit to the auction site, the cost per registration, the cost per visit to the respective property, the cost per bid and the cost per winning bid.