If a data subject reaches our website via a Google ad, Google files a conversion cookie on the information technology system of the data subject. The definition of cookies is explained above. A conversion cookie loses its validity after 30 days and is not used to identify the data subject. If the cookie has not expired, the conversion cookie is used to check whether certain sub-pages, e.g. the shopping cart from an online shop system, were opened on our website. Through the conversion cookie, both Google and the controller can understand whether a person who reached our website via an AdWords ad generated sales, i.e. executed or canceled a sale of goods.