This is not equivalent to cookies. Cookies allow you to specify arbitrary data, not just a session ID, so you can set preferences without having to hit a datab

This is not equivalent to cookies. Cookies allow you to specify arbitrary data, not just a session ID, so you can set preferences without having to hit a database or even running a completely static page, using javascript to read the settings. Cookies as they are now already allow you to control persistence. You can edit or delete them however you wish.