I truly believe that nobody can twist the arms of those who are not willing to pay for ebooks to actually pay for your ebooks. Those people will always hunt for freebies. And if the freebies are NOT available, they will check Torrent and download the pirated copies free anyway. It happened with many of my books.
With those free-loaders and hoarders, you can’t win. But the point of KDP Select is to build a lot of affiliation. If a book of yours does not sell and you do not promote it through KDP Select promo, it will just be sitting there pretty by itself. Very few people will ever stumble on it since it will not pop up in any category ranking (Amazon only list the top 100 best sellers of each category.)
On the contrary, when your book takes a ride on a KDP freebie promo, it builds extensive, random affiliation, such as “Buyers who viewed Joyland also viewed [insert your book title here]” or “Buyers who have purchased Fifty Shades of Grey also bought [insert your book title here]” (since free downloads are considered “Amazon verified purchase” in Amazon’s book.)
The rest is statistics. If one out of one hundred of those random affiliation brings you one sale after the promo and you have had three hundred free download, you will sell three copies. Math will never disappoint you. That’s why you want more people to download your book when it is free. In this hypothetical example of one to one hundred sales to freebies ration, three thousand downloads will give you 30 sales.
Of course, you can do a lot to maximize the return of these free downloads, particularly during the downloaders’ visits to your book page.
I wrote a book recently to discuss the wonderful and effective things you could do to retain the visitors’ attention and also sell them your non-freebie title, or at least to try the free samples.
Take a glance of my book on this subject to see if it can be of any value to you: http://amzn.to/1evdevT.