Recently there was a thread on the O’Reilly Radar started by Tim O’Reilly posting a chart that I put together from our book sales data. The chart showed comparative market share for most of the relevant programming languages. I have updated this in the chart below and have included 2005 data as well.
A litte insight to the numbers behind this graph. The percent shows that a lanugage like Java represents ~23% of all book sales when looking at the language dimension. That means, I compared all the languages and which books have ‘XYZ using Java’, or ‘Embedded FOO on Java’, etc. So it does not have to be a strict Java Programming book, but rather a book that is Java-centric or the examples contain mostly Java code. I compared aggregated sales units during Jan-Feb for 2005, 2006 and 2007.
This is not an exhaustive study as I threw out Languages that did not have a representative sample in one of the years. In other words, if a language area show up with 15 units in 2005, but not in 2006 [or 2007] it was dropped. These are the bottomfeeders. So if you use one of those languages, Squeak, you will not find the results in my chart.
During the previous two years and this year, during January and February, the biggest declines were seen with Java ~5.5% down, C/C++ ~4.5% down, Visual Basic ~2% down and Perl ~1.5% down. The reason I point these out, is that is is market share for books, the unit sales numbers, which I will not supply, are a bit more alarming if you are on the declining list.
So when you look at the top for both lists, the totals are a bit different. There is a 3% difference on the winners side. What is says to me, is that most of the growth was seen in the four top languages, while the decline was spread a bit wider.
Do you really care about languages and what books sales tell us about trends? Don’t think for a moment, as past posters have said, that some languages have better market share because one language has ’sucky’ books. I did a quick analysis of GPA ratings on Amazon by language, and there are not any really significant wins for one language over another. One thing that does factor tough, is early to market. On average, when a language or technology topic is in its infancy stages, the market is more forgiving on the reviews. About .5 for the first books to show up in a category. You could say the the first are usually the best, but that does not hold up either.
If there is enough interest, I will follow up with some efficiency and average title metrics.