Now that I have blog stats to check, I have lost valuable time that could be spent checking the amazon.com sales rank for my book. Thank goodness, because the book is tanking, to be perfectly honest. I am currently about 70,000th on the bestseller list, which is sobering. I started out somewhere below two million, and peaked around 3,000. I don’t really think these rankings are a very good indication of sales for textbooks, since most people buy them at their college bookstore, but a higher ranking is nevertheless to be preferred over a lower one.
For those of you who haven’t heard, the book is a graduate-level introduction to general relativity. There are many good books on the subject already, but I thought there was a niche for a modern book that focused on providing a clear, pedagogical introduction to the subject, rather than being overly ambitious and including too much advanced material.
The book came about in an interesting way. I first taught GR when I was a postdoc, and at the time I was young and foolish enough to think it would be fun to type up very detailed lecture notes and hand them out to each class. (Now that I am old and wise, the very thought makes my head spin.) Word got around that the notes were useful, and I began to receive requests for copies, so I just went ahead and put the whole collection online. They’ve been quite popular; the counter on the web page for the notes has passed 100,000, and that doesn’t include the many folks who download them directly from arxiv.org. Of course not nearly that many people have read them, or even printed them out, but it’s nice to be noticed.
The actual book is an expanded version of the lecture notes; what’s in the notes comprises perhaps half of the finished book. And of course the exposition is cleaned up and improved throughout in the book version. Still, it has been questioned whether anyone would pay for a book if much of the material was available online for free; indeed, certain publishers insisted that I would have to take it off of the internet (as if that were possible) if they were to publish it. But the nice folks at Addison-Wesley loved the idea of keeping the notes online, as basically free advertising for the book. They did a great job at the actual book production (spiffy cover etc.), although the price is somewhat high ($80). So this is something of an experiment in the relation between free online content and expensive tangible content.
By the way, I did not review my own book for amazon.com, like some people do. Even though my reviews have been good, I would have gone into much more loving detail.