[aartav]

I have real experience in this. I wrote and published two "big" technical books which were released through a major technical publisher. Both books were "mass market" in that you could find them on any bookstore computer shelf, they were translated into multiple languages, and used as course curriculum at several colleges. My caveat is that unfortunately my real world experience was a while ago. 20 years, which is a long time in this space. Distribution, self-publishing, and better online resources mean that YMMV.

I made a decent royalty, with a bunch of other terms which included buy-backs (e.g. returns) and other ways for the publisher to ensure they maximized their profit over mine. Over the course of 5 years I made roughly $35-40k, but that was spending a full year of 25/hrs a week on top of my day job, it works out to about ~$30/hr. I think if I were to quit my day job, continue cranking out 2-3 books a year, and collecting residual revenue, it would still be less than a 6 figure income (this was circa 2000 so $100k was +/-$160k equivalent) - certainly quite livable but also not stellar given that you have to be at the top of your field and on top of technologies all the time. My salary and my "side gig" contract rate were both hire at the time.

So...

Did I make much money? Not really.

Do I regret writing two books? Nope.

Am I proud of those books? Hell yes.

Would I do it again? Hell no. Way to much work.

[thawkins]

I have authored 3 tech books and quite honestly I would not do it again, the shift to ebooks has allowed the publishers to cut the royalties paid on electronic deliveries, even though thier costs have been cut. I found that the majority of sales were ebooks, plus you often find your books sold onto platforms like O'Reily where you receive no royalty. It also appears that translations cut the author off from royalties, one ofmy books was translated to Korean and I stop getting any royalties on that set of sales.

[GianFabien]

As I understand it, with self-publishing your income per book might be higher but you have to do your own marketing, publicity, etc. Publishers tend to generate higher volumes but also rake more cash their way. Afterall, that is their business model.

[itcrowd]

Could you elaborate whether you had a book deal in place before you began writing the (majority of) the book? And, what are your current thoughts on book deals?

I feel this is relevant to OP's situation given that I am assuming he has no such deal in place currently.