An application program interface (API), enables web development tools to interact directly with a hyperlink database subsystem. Tool developers use this API to design functionality that enables affiliates to log on to the hyperlink database system and generate merchant links. In response to requests from vendors' tools, the invention API uses the XML format to deliver requested hyperlink generation information. The requests are encrypted for users' privacy. The returned hyperlink generation information includes lists of merchants, lists of hyperlinks to the merchants web sites, the HTML code supporting the hyperlinks, and graphics for the links. Users implement hyperlinks by selecting among the choices returned in the response to the request and graphically placing (i.e., by drag and drop interaction) the resulting hyperlinks on subject web pages in a simple, error-free manner.