Use the Product Advertising API Scratchpad tool to troubleshoot your requests.
Verify that Product Advertising API is running correctly.
To do this, open a browser window and submit a REST request. This will confirm that the service is available and responding to requests. Normally, Product Advertising API is available 24 hours a day, 7 days a week.
Check that you are specifying inclusive response groups.
You may not receive the expected information in your Product Advertising API response if you have specified a response group(s) that does not return the data you want.
Check the structure of your request.
Each Product Advertising API operation has a reference page. Double check that you are using parameters correctly. Try the request on one of the other locales. If SOAP is not working, try your request with REST through your browser. That will help you determine if the problem lies with your code, your SOAP client, or with Product Advertising API.
Try your request with multiple ASINs or keyword/title search strings.
The Amazon catalog is extremely large and sometimes individual products have irregular data results.
Check how quickly your application is submitting requests.
If your application is submitting requests faster than once per second per IP address, you may receive error messages from Product Advertising API until you decrease your rate of requests.
If your application is trying to submit requests that exceed the maximum request limit for your account, you may receive error messages from Product Advertising API. The request limit for each account is calculated based on revenue performance. Each account used to access the Product Advertising API is allowed an initial usage limit of 1 request per second. Each account will receive an additional 1 request per second (up to a maximum of 10) for every $4,600 of shipped item revenue driven in a trailing 30-day period (about $0.11 per minute). You can verify that your sales are being attributed to your calls to the Product Advertising API by checking for the following:
You are using the links provided by the API when linking back to Amazon.
Your Associate account and Product Advertising API account were created using the same Amazon account (i.e. email address).
You are passing your Associate tag in all your requests to the API.