I know this is a review site, but many sellers rely on big giveaways to 'feed' Amazon's algorithm and improve the rankings for products.
I have been doing big, 100% free giveaways for a long time, and always saw very good results (page one rankings for competitive terms). I launched a new product recently, gave away nearly 200 units through Amazon, and ten days later I have not seen any ranking improvements at all. It is not possible to find the product on Amazon through the main keyword (it's probably on page 50, or something). It has horrible rankings for all secondary keywords as well. In spite of its growing review profile, it struggles to sell as it doesn't rank for a single keyword.
I am pretty certain that something has changed. I'm guessing that Amazon has changed its algorithm so that 100% discounted sales no longer affect rankings in any way at all.
Interested to know if anyone else has experienced this.