The website which was last visited by the user will be stored as a URL-address and it will be transmitted through the HTTP header to the website, which will be next visited by the user. By now, this is a common procedure. But it isn't sure if this method tolerates data protection. For the website providers this information is important. You can analyze from which page most of the visitors came. Did the visitors come via a search engine, if so, which one? Or did they come through link partner sites? The previously highly frequented sites are the most valuable business pages of a search engine optimized website. Accordingly, the business contacts will be deepened and refined. An analysis of the referring pages is useful for advertising, because the values of a calculation of the effectiveness of advertising can be measured on the other website. Here you can see, whether the cost factor expects advertising. Referrer pages provide a basis for a detailed analysis of consumer behavior in certain marketing activities.