Why does my website need Site Add Ons service?
Since each of Communilink hosting plan supports either PHP or ASP, if your website require both environments at the same time, Site Add Ons serivce is required.
Your website need a master and sub environement. For example, www.yourdomain.com(master) parks with the Unix Platform service which support PHP and www1.yourdomain.com (sub) has a Site Add Ons serivce which is Window Platform and supports ASP.