No real problem, it's just the way your cookie is crumbling on this one. There is no exact rule for a conversion and maybe if you ran more experiments you would get that magic 1/100 basis point.

You just need some more testing to see what is going to work best for you. As the famous Kenny Rogers song goes, you gotta know when to hold em and when to fold em.

105 clicks is not really that many to base any assumptions on, or even make a very rough conversion ratio

Although with over 14000 impressions I would say that your ad positioning needs to be looked at (which may be due to your ads QS) and/or the actual text of your ad needs to be looked at (more than likely this would need to be tweaked)

Have you got attention grabbing & keyword relevant title?

Have you got a compelling & keyword relevant description?

Have you got a good 'call to action'?

Hope that helps

Steve

I would suggest that you try testing with a landing page loaded with pre-sell content.

get your visitors into a 'ready to buy' mode before sending them to amazon.

don't get discouraged... I once had a campaign that had over 2200 clicks and zero conversions

I agree. I remember doing some campaigns in adwords - it was a little rough. I had to do nothing but test - and ask a lot of questions...

Just a final thought but if your sending traffic straight from the search engine to amazon, even if you make a sale they wont pay you. I suggest you read their T's & C's