This could be for several reasons.
If you're ordering one of our Shiner packages of 4, 9, 12, and 24 blocks they are already at discounted pricing, so they cannot be combined with any other promotion code. This includes any flash sale, holiday sale, or welcome discount code that has been emailed to you.
If you're using a Gilt City, Groupon, Zulily, or Living Social voucher code, please double check the expiration dates. Also, double check each digit in the code to make sure each one is correct. Often times capital "O's" or "I's" look like zeros or ones.
If you need any further assistance, please email us at firstname.lastname@example.org.