Don’t make me enter details more than once !!
There is nothing worse tham going to any website and having to enter your email address or delivery details (or anything repetitive for that matter).
I know this breaks with current cookie convention but maybe use a clear and concise disclaimer. Maybe even display your disclaimer in a pop up – but only ONCE.
If somebody enters information, it should be used to follow them through your site/s.
NEVER share you cookie info or customer info with 3rd parties !