I asked someone who does this. Somewhat transcribed comments:
Expect $0 to $3k from a really shitty publisher who is probably just going to waste your time, or a serious publisher who believes you'll waste the publisher's time, or both.
$3k to $6k from a publisher who has some clue, but the topic is extremely niche. ("Pentesting South African Wifi Networks with Monads")
$6k to $12k from a publisher with some clue for a book that will sell fairly well to a big niche developer audience - something like a developer guide to Android or iOS.
$12k to $25k for super-popular consumer tech books for mainstream topics like macOS, iOS, and so on.
Royalty rates are 8% to 12%, maybe 15% for someone with a track record. (8% and $5k is standard for mid-list unproven fiction. Tech rates can be higher.)
Watch out for comedy royalty rates on ebooks. (15% on a downloadable file? 50% or GTFO.)
True: advances don't usually earn out. And if you write more than one book the unrecouped advances get added together, so you will never, ever, earn out, unless a book becomes an unexpected best-seller.
Which it won't, because publishers do not promote books. There's a sell-in period aimed at store buyers before publication to get the book on physical shelves, but otherwise publishers do somewhere between exactly zero and almost zero marketing and promotion.
Bottom line: writing books on its own is largely a waste of time, unless you want to research a topic and get paid to learn it and don't mind producing a book to pay for the payment.
Writing books as shop windows for other tutorial content and/or consultancy can work very well.
People who know what they're talking about, can write to a deadline and make sense, and are willing to accept pocket money are incredibly rare. Publishers often trawl for new writers, and if they find someone who is all of the above and not too easy to flatter they may be willing to push the advance higher than usual to close the deal.
If you are going into a book contract, familiarize yourself with cross-accounting or basket accounting clauses, and get them stricken from the contract. (This is the clause where you need to earn out all the books before getting royalties for any of them.)
In general familiarize yourself with book contracts, and understand the pitfalls. Or consult a literary lawyer.
Source: I'm the author of multiple tech books over more than a decade and several novels.
The basic shape of the contract is the same. The publishers I have worked for are both fans of plain language and relatively short contracts, which helps. (Tech publisher is Pearson, fwiw, and they have been wonderful to work with over the years.)
The differences in how I write are pretty epic. For a tech book I'll work out a very detailed outline (down to subheadings within each chapter) in advance, and need larger slabs of time to write to maintain my train of thought. For novels I tend to work from a much lighter-weight outline (major plot points, not chapter by chapter) but spend a bunch of time in advance thinking through the characters and world-building.
> because publishers do not promote books. There's a sell-in period aimed at store buyers before publication to get the book on physical shelves, but otherwise publishers do somewhere between exactly zero and almost zero marketing and promotion.
I'd be interested in hearing more about this. Why is it that publishers don't promote books?
Expect $0 to $3k from a really shitty publisher who is probably just going to waste your time, or a serious publisher who believes you'll waste the publisher's time, or both.
$3k to $6k from a publisher who has some clue, but the topic is extremely niche. ("Pentesting South African Wifi Networks with Monads")
$6k to $12k from a publisher with some clue for a book that will sell fairly well to a big niche developer audience - something like a developer guide to Android or iOS.
$12k to $25k for super-popular consumer tech books for mainstream topics like macOS, iOS, and so on.
Royalty rates are 8% to 12%, maybe 15% for someone with a track record. (8% and $5k is standard for mid-list unproven fiction. Tech rates can be higher.)
Watch out for comedy royalty rates on ebooks. (15% on a downloadable file? 50% or GTFO.)
True: advances don't usually earn out. And if you write more than one book the unrecouped advances get added together, so you will never, ever, earn out, unless a book becomes an unexpected best-seller.
Which it won't, because publishers do not promote books. There's a sell-in period aimed at store buyers before publication to get the book on physical shelves, but otherwise publishers do somewhere between exactly zero and almost zero marketing and promotion.
Bottom line: writing books on its own is largely a waste of time, unless you want to research a topic and get paid to learn it and don't mind producing a book to pay for the payment.
Writing books as shop windows for other tutorial content and/or consultancy can work very well.
People who know what they're talking about, can write to a deadline and make sense, and are willing to accept pocket money are incredibly rare. Publishers often trawl for new writers, and if they find someone who is all of the above and not too easy to flatter they may be willing to push the advance higher than usual to close the deal.