In order to improve the efficiency and ensure that the features offered by the PA API which are most relevant to its users, we have restricted the PA API access to only active Amazon Associates, effective June 01, 2017. In order to reinstate PA API use, you will need to have a valid Amazon Associates account using the same email address used for the PA API account.
If you already have an active Amazon Associates account, please add the email address used for creating the Amazon Product Advertising API account as a primary or secondary email to your existing Amazon Associates account. Once the email address is added successfully, you should be able to access the Product Advertising API within few minutes.
If you have Amazon Associate accounts in multiple marketplaces, please ensure to add the email address used for creating the Amazon Product Advertising API account as a primary or secondary email to all the existing Amazon Associates accounts.
Verify that the email address used for creating a PA API account is updated as a primary or secondary email address in your Amazon Associates account.
You will receive an error if your Amazon Associates account is closed. Verify the status of your Amazon Associates account on Associates Central.
Amazon Advertising API Magento extension
Amazon Products Manager is an extension that allow you to import products from Amazon to Magento using Product Advertising API. As an affiliate store, you make money on the total basket, even if the buyer purchases something totally unrelated to the product link they followed from your store. You can try the demo.