Account credit can be spent on our site toward any purchases. You can get account credit from several sources - from a Gift Certificate purchase, a gift sent to you from another account, or from to a refund to your account. You can see your available account credit from your Account page (in the Cart section)
To use your account credit, just proceed to the first checkout page (Payment Method) and check the box near the top of the page to Use Account Credit and then continue. The next page will show the credit applied to your order and you can see the final price before completing your order. Any credit that you have over the cost of the order will remain in your account.
If you have affiliate credit (different from account credit) that you are trying to redeem, you can find out how from our Affiliate Program articles along with other important information for affiliates.