No. In fact it is easier to redeem your promo code first. It will then walk you through the account creation steps so that you can read the book on the device of your choice. After entering your promo code and selecting the "Redeem" button, you will be prompted to create a new account. After you've created your account, you will be redirected to a confirmation page (if the promo code was correctly submitted) with follow-up steps detailing how to read your ebook.