Surely you don't expect that your time spent writing a book is going to pay out at $300 an hour, or whatever your consulting rates are.
I think bdunn and robbiea's suggestions are valid.
(And, man, I wish pyre's suggestion that I don't need money was true :o) though I'm lucky enough to consider myself pretty successful at what I do, so I wasn't writing to make up for missing revenue.)
But, in addition to the residual income and, to a lesser extent, publicity angles, the initial spark behind writing it was the fact that I found myself being asked time and again about what life is like as a contractor/freelancer. Which meant that a) there was definitely a knowledge gap/problem to be solved and b) the repeated nature of similar requests meant it made sense to optimise how I shared what I'd learned over the years.
I'm well aware that no one gets rich from writing a book - so I deliberately didn't sacrifice any client time; I was able to (just) fit it into what spare time I had.
Along with all that, there's the fact that I knew I could write this book and wasn't intimidated by the task (I had the knowledge and the skills -- I used to be a national-level journo) and the fact that writing is still fun, so it was a pleasure to make.
Yep, that pretty much covers it.
This was the same impetus behind indieconf, the conference I run in November (shameless plug - http://indieconf.com - we might even get bdunn speaking this year).
Products: Long term, residual income and the ability to build up an email list that you can market to with other offerings.
Fork is a system call.
The only reason I point it out is that I find it difficult to take anyone who posts titles like this seriously.
Edit: sorry, I posted reflexively before reading other comments. Turns out I'm not the only one who values Smalltalk to the extent that I actually want to remember something about it :)
The Leanpub page contains a run-down of the main sections and (now that the book is published) also auto-includes the real table of contents - not sure if you've scrolled down the page all that way (it's quite a scroll to get there).
For what it's worth, of the experienced freelancers I beta-tested the book on, the key peice of (pleasing) feedback that I got was a bunch of them all saying "I wish I'd had this book X years ago, when I started out".
Buying now. I'm especially interested in the "Oiling the wheels" section.
Also, if the cost of a $39 book that might be able to help you raise your rates, thus resulting in thousands of extra dollars is too high... Well :-)
I'm talking about questions like: how to allocate the different people to different tasks, how/when to hire employees, hiring on-site employees vs. hiring freelancers who work from home (potentially form elance or similar), etc. Does this book get into any of these topics at all?
By the way, I've heard the book "Design is a Job" praised on HN as a freelance Designer's guide to freelancing. I'm currently reading it. It seems your book is very similar in its goals and content, only for programmers instead of designers. If I'm right, I would definitely consider marketing it as "Design is a Job - for developers", or at least include that message somewhere on the leanpub page. I know I looked for it.
Someone over on the Leanpub page has asked about how UK-centric it is, so I thought I'd post pretty much my answer to that question here, because I think it's relevant:
"The majority of the book is relevant to going freelance wherever in the world you are. There are some sections, though (basically the money and legal ones) where, because I have first-hand experience of operating in the UK, I've framed it in UK terms. However, the principles/topics covered are still pretty relevant wherever you are in the world and will set you on a decent path to finding out about the local equivalents.
While it's impossible to write a book that covers legal/financial stuff relevant to the whole world in one go, I do want to add in more territory-specific detail where people ask for it. So, in a future release of the book (which you'll get for free, remember) the plan is currently to refactor the UK-specific stuff to be generalised and then 'add support' for versions of that info applicable to additional territories (most likely in an appendix, but I'll see how realistic that is when I've had more feedback about the territories people want the book to cover).
But, like I said, the advice in most the book is location-independent."
I am actually resident in the UK and buying a copy shortly!
Taxes, accounting, legalities, etc. can all be localized by doing a little Googling.
Still, I'm thinking about going freelance, the book is reasonably priced and the table of contents looks interesting.
For a little more depth on the business side of freelancing, I strongly recommend the following book: Working for Yourself: Law & Taxes for Independent Contractors, Freelancers & Consultants, by Stephen Fishman J.D.