http://www.johnhiltoniii.org/responding-to-comments-about-%E2%80%9Cthe-short-term-influence-of-free-digital-versions-of-books-on-print-sales%E2%80%9D/

it seems to have been demonstrated in some measure that offering v. 1 of a series helps to draw new readers to v’s 2+. can offering 1 title free help non-series multiple-book authors? how about new authors offering their book for free in e-format for a few weeks, to get people to read and review it? or do certain special people have to read and review (e.g. nancy pearl). and: do we have a real idea of the effect of word-of-mouth? there are many possible models. doctorow’s model is unique, and perhaps not broadly applicable. taking myself as an example: i’ve downloaded most of his books for free, not yet read any, given a print copy of one to a relative, and then been commanded by a colleague to read that precise title. that colleague did not know that i had downloaded it for free, or that i had gifted it in print.

The study cited in this post was an attempt to generate some “crunchy data” where we could look at actual sales figures for multiple books as opposed to just anecdotal stories. I hope that many other publishers and researchers will do more studies in this area.

As we stated in the article, “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.”

To the extent that this article stimulates discussion and action regarding the need for more and better research in this area, I am happy.

Of course all of this is subject to change if people’s reading habits shift to reading electronically, thus providing more reasons for future research.

Little can be (or should be) concluded from their elementary analysis except as an example of how one ought to be more cautious with data. The fact that the authors are a professor and PhD student is inexcusable.

In that regard, I do think trade publishers have done little to support or join data-driven research efforts. That’s one of the reasons that Hilton’s data is general: he can’t get the specific feeds without publisher’s permission.

My sense is that you rightly see a number of holes in Hilton’s methodology. Given those holes, until we collate and evaluate a critical mass of experiments with free, we really can’t know if there is or is not a general approach (or even what approaches work).

I’ve proposed a segmented research approach to a range of trade publishers, offering shared results in exchange for data that would be disclosed only to the extent that the participating publisher approved. To date, one publisher contributed experiments with “free”, and two are participating in an effecort to establish the impact of piracy on paid content sales.

David, I agree with you about O’Reilly; they are one of the two participating publishers on the piracy study. They also are the publisher for the 2009 paper I wrote on the impact of free and pirated content on paid sales. I think you’d find O’Reilly both surprised and perhaps as frustrated as I am that other trade publishers are willing to spend tens of thousands of dollars annually on enforcement options like Attributor without doing work to establish the impact of piracy.

I agree with both of you that we could use better and more scientific research in this area. In my experience, small data sets limited to imprints and even larger publishers are not adequate to get those results. Well-planned, financed industry surveys would be a benefit.