A recommendation appliance, system and method are provided for generating and deploying additional web page content or functionality (e.g., retail recommendations) to an existing web page server system. For example, the present invention may be embodied as a reverse proxy server that is inserted as an intermediate network node between a web server and the end users accessing the web server. In this position, the recommendation appliance can introduce recommendation messages to web pages generated by the web server without requiring any modification to the code or architecture of the web server. In addition, the appliance may separately track the transaction activities of end users who receive recommendation messages and the transaction activities of end users who do not receive recommendation messages, so that a comparison of the effectiveness of the recommendations may efficiently be demonstrated without requiring any modification to the code or architecture of the web server.