The Popularity of Christian Books

Intro
I have been thinking a lot lately, as my last few posts may have indicated, about just what American Christians are reading. This has been fueled not only by my own reading of The Shack, but also by my discovery of two great websites. One is a blog by an author named Tim Challies, the other a companion site called Discerning Reader. Neither site is perfect, of course, but both are very interesting.

Anyway, this got the nerdy side – it’s a big side – of my personality fired up, and I started wondering what American Christians are reading, and what they think of it. So, I conducted a little study of Amazon reviews of popular Christian books to see how various books were rated. (Warning: extreme geekery follows…)

To skip ahead to my actual findings, click here.

What I Did
This graph (click to enlarge it) is a summary of the various “star” rankings on Amazon.com of popular and/or historically significant Christian titles, as a percentage of all reviews of a given book, as of March 5, 2008. That is, every book gets a line; the colors indicate how many reviews gave a book a certain number of stars.

The raw data is available here.

Methodology
If you’re interested in methodology and possible flaws, read the next paragraph; if you don’t care, skip that paragraph and see my thoughts below.

To collect data, I simply collected the number of each type of review from each book’s page on Amazon.com and entered them in a spreadsheet. Before I could make much sense of this data, I had to make a few assumptions:

1. Amazon.com reviewers are representative of book readers in general, and Christian book readers in particular. This at least seems reasonable, given Amazon’s massive market footprint.
2. Amazon.com reviews are representative of public sentiments about a book. This seems unlikely, since there is probably a strong bias toward people who bought the book from Amazon; if most reviewers are buyers, we might expect strong upward skewing, so that most reviews of most books are positive. This seems likely, but making the further assumption that the bias at least affects books more or less evenly (which seems questionable, but reasonable) reduces the impact of any positive bias at least somewhat.
3. Amazon.com readers are a representative sample of readers of both very old (e.g., The Divine Comedy) and very new (e.g., The Shack) books. This is unlikely, since classics seem to garner lots of readers and few Amazon reviews, while The Shack, in particular, is spreading largely through word-of-mouth (viral) marketing.
4. Amazon.com reviews provide an adequate sample size for meaningful analysis. While this is very likely true for a book like Left Behind, with 2,169 total reviews, it is almost certainly not true for A Pilgrim’s Progress, with 18, or Knowing the Will of God, with zero. The other books fall in between these extremes, and the sample size may be a fatal flaw of my analysis. Additionally, a meaningful number of reviews – 22 – for Paradise Regained was available only for an edition which includes Paradise Lost, making that data suspect. No reviews at all are available for Knowing the Will of God, despite what I believe is a fairly good reader base.
5. Amazon accurately groups reviews for multiple editions and publishers of one book. This is suspicious, but appears (by the “looks okay to Ed” method) to be significant only in the cases of one or two of the oldest works I included. To compensate for any biases, rather than spend all my time looking at multiple editions and imprints, I just picked the one with the most total reviews.

Discussion
Two discoveries stunned me about this little exercise. First, The Shack has some amazingly positive reviews – 87.8% were five-star reviews, 91.7% were four or five stars, and a whopping 95.1% were three or better. Only The Pursuit of Holiness (at 88.2%) and Knowing God (at 89%) got more five-star reviews, and only seven and six books, respectively, beat The Shack on the other two measures just mentioned. But, The Shack, only on the market for ten months, already has 205 reviews, while The Pursuit of Holiness has only 34 and Knowing God only 73. This tells me that the reception so far of The Shack is overwhelmingly positive, even compared to that of other books, and that it is being read widely compared to some books that may actually be more widely recognized.

Second, I found it very interesting which books were bringing up the rear in the five-star rankings race. Out of 23 books in this little study for which any data exists, The Shack performed third, as I already noted. Other wildly popular books did not fare nearly so well. The popular Conversations With God came in only 15^th, Left Behind a weak 17^th, the wildly successful The Purpose Driven Life a surprising 19^th, The Case for Christ in 21^st, and The Prayer of Jabez a pathetic last place.

Conclusions
What does this all mean? It appears that most popular Christian books – even classics like The Chronicles of Narnia – experience a significant trailing off in support and, in many cases, a backlash when they have been read widely enough. It also means, however, that The Shack despite being reviewed 205 times already, is not experiencing this, yet – it is claiming a popularity greater than that enjoyed by any work by Milton, Lewis, or McDowell, to name a few, and it is still largely unknown to the public.

It’s possible some books get widespread press and attention despite always having a vocal opposition – in which case The Shack truly is ascendant, since it has so little opposition – but it seems more likely to me that the book simply is a long way from peaking. We should expect to see more like a thousand reviews, as a ballpark guess based on other super-popular books in recent years, many of them negative, before we can say that The Shack has passed its peak.

I hope some of my readers will find this as interesting as I have and will start conversations (here or anywhere else) about both The Shack and what people are reading, more generally.

P.S. Just because I included a book in this study does not, of course, mean that I think it’s a good book or one I recommend.
P.P.S. For specific discussion of The Shack, see my posts here and here.