split test is the answer anyway, with amazon tracking ID. We can't know exactly which keyword make good conversion But in case, you have a website, and place amazon product on your website, Your website has installed tracking system, like google analytic for example In that case, you can track which keyword make good conversion or not Let try and good luck
The TrackingIDs is the best way for test your projects. But you can use it by 100 TrackingIDs in 1 account by the default. If you want more , you can email to amazon-support.
There has to be a better way to track conversions. I know you can track Amazon via Affiliate Radar but I don't understand where that information shows up. It added a &tag=idnumber but I couldn't work out where to find that information when I logged into Amazon. Has anyone used Affiliate Radar and Amazon for tracking? Or Xtreme Conversions? Does that work with Amazon? Jill