For some time now Amazon has had the content of books, to allow people to serch them (even if the book content itself is not available electronically). Now they provide a concordance for these books. As they say, "Concordance is an alphabetized list of the most frequently occurring words in a book, excluding common words such as of and it."

The concordance for Mastering Delphi 2005 is available here. The words appearing more than 1,500 times are: class (2,103 times), code (1,752), component (1,827), Delphi (2,004), object (1,521), property (1,503), use (1,827), while form misses the ranking by a mere 12 occurrences. But see it graphically on the page, it is much nicer than I could list here.

The page has also text statistics, including various redability indexes (where it doesn't perform that well), complexity of words and sentences, total size (the book has a whopping 2,195,725 characters), and relative price: you pay one dollar for 9,011 words. Not too bad!

Speaking of Delphi books, Nick Hodges recently posted an interesting blog entry on the topic. He praises mine and Xavier's recent books saying you don't need much else, claiming that "there doesn't need to be that many good Delphi books out there". This might be partially true, and I appreciate his words ("If you have Marco's book, for instance, you really don't need any other books."). However, things are more complex. My book is selling OK, but it will probably sell a quarter of the copies it did a few editions back. There are many reasons for this (people bought earlier versions, people now know Delphi, there is so much on the web...), but overall if writing books turns in much less money, authors aren't really encouraged!

I fully agree with Nick, the publishing model needs to change. And I have actually already signed up with (one of the sites Nick mentions), looking forward to publish soon both ebooks and print-on-demand books with them. As authors/self-publisher royalties are many times than with traditional publishing, it might be economically worth writing even to sell a few hundred books. Stay tuned.