Amazon provides a Amazon Widget called Quick Linker. This widget can be used to easily add a affiliate link from your blog post back to a product on Amazon. For example here is one for WordPress for Dummies. If you already have a Amazon Affliate account it is just a matter of logging in and getting the script it generates for you. But where do you paste it? I couldn’t find anything that would tell me. I finally decide to paste it in the header.php file before the body tag. So far it seems to be working correctly. I did notice that when I edited a post with tags in it for the Quick Linker that the asin attribute was removed from the anchor tags. I don’t know why that is. I just put it back in and tried not to edit it again. If anyone knows of a better way to do this please let me know.
Amazon assigns a ASIN (Amazon Standard Identification Number) to each product they sell. There are two ways I’ve found to look them up. One is to visit ASINLookUp.com and use their free lookup tool. The other is just to look at the URL in your browers when you navigate to the item on Amazon.com. The URL will have either a “…\product\83726684\…” or “…ASIN\9383678\…” in it. This is the ASIN and can be used to identify the product in question. Try pasting it into the code you are using and you should see what you are expecting.