Free Your eBooks: See Sales Increase?

A just released study that looks at the relationship between free digital books and print sales has been published in the Journal of Academic Publishing and suggests some positive implications:

A growing number of authors and publishers freely distribute their books electronically to increase the visibility of their work. These books, for both academic and general audiences, cover a wide variety of genres, including technology, law, fantasy, and science fiction. Some authors claim that free digital distribution has increased the impact of their work and their reputations as authors. [1] But beyond increased exposure, a vital question for those with a commercial stake in selling books is, “What happens to book sales if digital versions are given away?”

One answer may come from the National Academies Press (NAP), which makes the text of all of its publications freely accessible. “Consequently,” reported Michael Jensen, Director of Publishing Technologies at NAP, “we are very well indexed by search engines.” [2] Jensen wrote that as a result of this indexing they receive many visitors, a small percentage of whom purchase books. Jensen reported that NAP’s 1997 publication “Toxicologic Assessment of the Army’s Zinc Cadmium Sulfide Dispersion Tests” had 11,500 online visitors in 2006. Those visitors “browsed approximately four book pages each. Of those, four bought a print book at $45, and two bought the PDF at $37.50. So 0.05% of the visitors to that particular book purchased it, even though they could read every page free online.” [3] Thus, a nine-year-old out-of-print publication that otherwise would likely have been inaccessible was viewed 11,000 times and purchased six times.
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The present study indicates that there is a moderate correlation between free digital books being made permanently available and short-term print sales increases. However, free digital books did not always equal increased sales. This result may be surprising, both to those who claim that when a free version is available fewer people will pay to purchase copies, as well as those who claim that free access will not harm sales. The results of the present study must be viewed with caution. Although the authors believe that free digital book distribution tends to increase print sales, this is not a universal law. The results we found cannot necessarily be generalized to other books, nor be construed to suggest causation. The timing of a free e-book’s release, the promotion it received and other factors cannot be fully accounted for. Nevertheless, we believe that this data indicates that when free e-books are offered for a relatively long period of time, without requiring registration, print sales will increase.