Well, the
announcement of the game I am writing a few days ago on this blog caused
my book to be sold out (the game is set in the universe of the book). There are a few copies available now again. And apparently, they also ordered more already. I wonder if amazon will notice that the demand goes up a bit and will order more to prevent that the book is sold out again soon. But at least if it is sold out all the time, it looks like my book is popular :)