Why does the clip length work by Cookie and not by username and login?

We find it hard to type on the iphones built in keyboard. Imagine to type in your user and pass everytime you want to watch a movie. Thats why we sent activation by email You will receive the mail, click on it and youre ready to watch movies longer than 20 seconds as long as your cookie is valid. At least one year or till you will clear your Cookies.