if your wanting to gain any type of traffic back to your websites, Amazon affiliate or not, you should go back and do at least some on page SEO, using the "ALL IN ONE SEO" WP plugin can also be beneficial. Furthermore, make sure that you add in content pages as Google does not rank highly any thin affiliate sites of any nature with just product links.
Once you have done some of the above methods than it would be time to build some back links, but you also want to do this slowly so it looks natural and not artifical. If, you do any of these methods to fast it can actually harm your site more than help it.
I would also suggest taking some time and read some of the answers that have already been provided here in the categories of Traffic generation, and affiliate marketing, and you should find some very helpful suggestions to get you started on the right path. Here is one helpful topic:
Hope my answer helps you ;)