The book is actually a tiny portion of those sales. I'm one of those rare guys that makes money off the thing the book is about and not that much teaching people about it. It does make some though so I include it in the calculations.

Mostly I haven't done much marketing for it outside of my blog so far. I've been toying with some other ideas for it, but I haven't really had the time to devote to it. Mostly it's just a side project I've had fun with.