webdevfv - 4:05 pm on Aug 28, 2013 (gmt 0)
I did a test run for 2 months using some popular products but the conversion rate was not impressive.
The thing is, if the product is not in stock or sold at amazon your Product Ad doesn't show - this would be a great time for it to show and give many conversions as you'd be one of a few select advertisers (maybe the only advertiser) who has the item the searcher is looking for.
If the product is in stock then the searcher is shown the amazon listings and if you're lucky your advert might also show once the user has clicked onto the product page. However, given the choice already on amazon it is unlikely that the user will then select your site above those prominently shown.
Basically you are picking up crumbs and even if your price is better than those above it is unlikely to lead to a sale.