Cookie stuffing

On the World Wide Web, cookie stuffing (also cookie dropping) is an affiliate marketing technique in which, as a result of visiting a website, a user receives a third-party cookie from a website unrelated to that visited by the user, usually without the user being aware of it. If the user later visits the target website and completes a qualifying transaction (such as making a purchase), the cookie stuffer is paid a commission by the target. Because the stuffer has not actually encouraged the user to visit the target, this technique is considered illegitimate by many affiliate schemes.