Packt seem to be a quota publisher. They're more focussed on getting a steady stream of titles out of the door than making those titles definitive, and they tend to spam anyone who looks even slightly competent. I know a number of people who had offers from them, and they're invariably low-ball compared to other publishers.

The top tier publishers pay an advance - which you probably won't ever make back, so you may as well consider it final payment for the book. O'Reilly like to pay nothing up front, so all you ever see are royalties. This can work well for a popular and timely topic. Niche titles won't pay much, although they can still be a good thing to have on a resume.

The really big money used to be in the mainstream - how to use Windows, how to set up an iPhone - but that's less of a thing now that a lot of people Google for help.

Sales figures for hardcore developer titles can be very low. Five figures for a developer title is a solid success. Six figures would be a wildly unexpected best seller, and seven figures a complete unicorn. Four figures are more typical, and high three figures can happen.

The catch with royalties is whether they're a percentage of the cover price or the publisher income. Publisher income can be 50% or less of the cover price, so that's a thing to consider when working out if a book project is worth the time.

With self-publishing, you keep a much higher proportion of the earnings. Anyone who is thinking about this should work some numbers through a spreadsheet. You'll find you can make the same money a publisher would pay with far fewer sales, and if you can get four or five figure sales - unlikely and very difficult, but not impossible - it's a nice alternative income stream.

If you already have any kind of following, it's a no-brainer. If you don't, it's a huge marketing effort, but you still get to have final say on the timing of updates and revisions, which can keep a title earning longer than a publisher would keep it alive.

This is accurate. I would add that, in my experience, the value-add of working with a technical editor to shape the book and stay on track is definitely worth the cost of an editor.

And then there are typesetters, copywriters, graphists, reviewers, marketers and distribution platforms that do a lot of the work of making a book successful. Sure, writing is critical, but bringing a high quality book to readers requires a lot of work that you have to do yourself when self-publishing.

Please don’t go ahead if it is for Packt. We had a horrible experience with them.

After a bunch of hunt we moved to what is called a first tier publisher. And the difference is so massive. We are now restructuring and rewriting all chapters. Our reviewers think it can be a landmark book. None of it could have happened with Packt.

I come from a startup world, and was partially able to stomach Packt at the start. But my co-authors have worked at Microsoft Research and Google AI. They just hated dealing with them. And in the end all of us decided we would rather self publish than go with them.

> Was it from Packt?

From a 1st tier publisher. ;) But I concur with another comment, it's hard to justify not going with self-publishing in 2019. More so if you're not doing this for money. I would prefer to publish a completely free ebook (like Pro Git, etc.), but it's hard to negotiate this with traditional publishers.

I am skeptical on the point that a good publishers adds no value.

In our case, we authors have been publishing papers for over a decade. And together we have almost 1000 citations for our papers.

And yet, we were not able to think over and improve on certain aspects of a book that we discovered only after talking to our current publisher.

Maybe if you are completely clear on what your book is about and how will readers react to it, a publisher might not matter. But for us, it seems it was not the case.

Even if you are expecting financial gains self publishing is still very valid. (I am talking from personal experience where my self published tech courses make more money that my editor published ones). Dont forget that even though editors do the marketing for you you only get a small fraction of the total sales. And also they might not be very good at the special niche you are targeting.