You don't enter them in as a promotional code....you enter them in as a referring customer. by clicking the link you already have the reference in place for your order. They DO NOT REMOVE THE 15% UNTIL AFTER YOU COMPLETE THE CHECKOUT AND THEY PROCESS IT. If it makes you feel better call them and tell them you want the 15% oiff and manually give them the customer referal number on the phone that way they will take it off before you "checkout"

Mine is 107149 BTW