Abstract: In a method of interactive advertising for the Internet, a commercial link for an ad space is embedded in the text of a Web page. The contextual targeting for the page is determined by analyzing the overall content of the page or determining the presence of individual keywords within the text content of the page. A keyword that is visually distinguished from the surrounding page content triggers an ad space to display a message, which may include a product related to the text. In some embodiments, the ad space allows a user to make a purchase transaction or view an inventory of goods and services, with descriptions, all without leaving the Web page. The web page is analyzed to determine appropriate keywords within the text to associate with the ad space. Upon user interaction with the keyword, an ad space according to the invention provides a customized message that is contextually targeted to the user.