Not that I know of, not anything current that is.
Did they perchance give you one after you placed an order? An incentive for follow-up sales is usually given afterwards and these vendor sites often prompt you for a 10% discount if you sign up for their SPAM email newsletters.
My advice is to take advantage of that, sign up, and even sign up under a different email address/new account then place another order using that. It's a little hassle (I loathe spam) but I've exploited that loophole 2-3x now on other sites.