In May of this year, Freebooksy commissioned a survey of authors who had used KDP Select’s free promotion days between January and April 2012.
72 authors completed the survey. Some of these authors had been featured on Freebooksy, some had not. We posted the link to the survey in Kindle forums and groups to get a cross-section of respondents.
The findings of our survey are below. We have opened up our survey for authors who conducted a KDP Select Free Promotion between May and August. Please help us to provide this data by completing the survey now.
Book Profile
Of the 72 books that ran a free promo:
Average number of reviews = 17
Average review Score = 4.2
Average Price = $3.09
Median Price = $2.99
Genre Breakdown:

Free Downloads
The average number of days a book was free was 2.36 with 2 free days being the median.
Average number of free downloads = 6,972
Median number of free downloads = 4,004
Least amount of free downloads = 74
Most amount of free downloads = 35,400
The number of free downloads was most positively correlated with the # of reviews a book had. So, the more review a book has, the more likely someone is to download that book free.
This makes sense as readers like to know that content has been vetted before spending time downloading and reading it, even if the content is free. The number of reviews acts as a validator, telling the author that many people have read and reviewed this book so it is worth downloading.
Notably, the review score does not hold the same predictive power, perhaps because readers know that not everyone will like the same material (the bestselling book on Amazon today, Gone Girl, has just as many 1- and 2-star reviews as it does 4- and 5-star reviews) but just knowing that many people have read the book, gives them comfort.
Authors also see more free downloads if they offered their book free for more days, but the average number of free downloads per day is greatest over a 2-day free promotion.
Sales Spikes
To control for price distribution, we looked at sales spike by units of books bought before and after the free promotion days.
Average number of books sold before promotion (per week): 19
Average number of books sold after promotion (per week): 141
On average, authors saw a 6-fold increase in book units sold after their promotion ended.
Median number of books sold before promotion (per week): 5
Median number of books sold after promotion (per week): 49
Most authors saw an almost 10-fold increase in book units sold after their free promotion.
The sales unit spike was most highly correlated with the number of reviews a book had, the # of free downloads a book had and being featured on a 3rd party site.
This makes sense as the more downloads a book gets, the higher it ranks on Amazon’s Top 100 Free charts. When the book goes back to full-price, Amazon tends to keep the book listed on the charts for at least a few hours, giving the book exposure at it’s full price.
Similarly, if the book is featured on a 3rd party site, the book feature stays up on that site giving it visibility for a few days at full-price.
Marketing & Promotion
On average, authors spent $20 promoting their free promotion days, with the maximum amount spent being $500.
Half of the authors promoted their free days on their website, 78% of authors promoted their free book on Facebook & Twitter and 67% were featured on a 3rd party site. 29% of author sent an email to family & friends and 15% sent an email to their fan list.
Being featured on a 3rd party site and promoting the free days on Facebook & Twitter resulted in more free downloads and a higher unit sales spike.
87% of the authors plan to run another KDP Select free promotion in the future.
Takeaways for Authors
- Run your promotion for 2 days
- Make sure your book has at least 10 - 15 reviews
- Promote your free days on Facebook & Twitter (if you don’t have pages yet, set them up)
- Tell 3rd party sites about your promotion in advance (At Freebooksy we need at least 5 days notice for editorial features, and 48-hours notice for paid features.
Don't foget to take the current survey so we can provide this data to you again in a few months!