1. OP isn't as bad a designer as he thinks. The goal isn't a beautiful page so much as "no trust destroying indicators" like weird fonts, bad formatting etc. Good Job!
2. OP could probably double their sales by offering the first chapter for free with email signup on the landing page and then offering a time-limited discount as part of an email sequence.
3. We (in the dev space) have a weird view of these sorts of things as we make relatively so much in salary. But $400/mo is a decent car payment, another way to thinking about this is that OP wrote himself a free car.
4. OP could have taken all this knowledge applied it in his job, etc. but by making this very public and consumable objective proof of his knowledge he's put a solid milestone in his career path. I've friends that have done similar and then picked up six figure consulting gigs, lucrative job offers, etc.
All around, I just want to say nicely done and that I would love to see more developers do similar.
For point 2) yes that's something I could have tried, I see a lot of people doing this so I guess it works.
About point 3) I know that for SF folks making 150-200k / year, $400/month is like pocket change. Just keep in mind that in other countries, like France (I'm French) and many other European countries, a Junior dev is making 30-40k€ on average, and Senior around 45-55k€ (1)
My co-author and I figured out that a positive feedback loop is key. In addition to our API Design Book at http://theapidesignbook.com/ my co-author and I have a weekly newsletter at http://bit.ly/apiWeekly then he followed the consulting route using those for lead generation while I did some classes for Lynda/LinkedIn Learning: https://www.linkedin.com/learning/instructors/keith-casey and in both cases, we refer back to the book and the newsletter. Then in my day job at Okta, I talk about the same topics and occasionally refer to our stuff among other things as "for more information."
Most of it is free, a few things are paid, but everything builds and complements each other.
No matter where anyone finds us, the threads lead to the other things. This allows people to understand the basics of APIs, learn some advanced topics, and generally stay up to date on the space as a whole.
They all seem much happier.
1. Try raising prices by 50% for a month, see if your actual unit sales decrease.
2. Record a video for each chapter and then offer that at a (much) higher price point. $250+ - combine all this together and I bet you could crack $1k/mo.
Thanks for sharing. For technical topics, I think reading is much faster and reliable because readers can skim and also copy code. I'm curious why it might be effective to produce a video and price it higher?
Could you give an example of what kind of a font would be a "trust destroying indicator" ? Maybe comic sans I guess, but I have a feeling you mean something more subtle.
What are the percentage of people that would make the the first chapter in and fail to convert - vs the people that would have bought then likewise never finished?
Because I have the entire book online, people are much more likely to reference and point other people to it because it's a complete useful web resource. If, say, someone on Reddit asks about learning some architectural pattern, it's natural for someone to say "Oh, check out this book here." It's less likely they would say, "Oh, check out this page which just describes a book that you have to buy to actually answer your question."
So my book is much higher profile than it would otherwise be. A lot more people are discovering my book and coming into the funnel. The fact that they can read the whole thing without paying probably means a smaller fraction of people buy it, but the increase in the total number outweighs that.
Also, giving it away for free gives people a lot of gratitude towards me and that in turn can cause some to buy it. It feels less transactional to them because they don't have to. In fact, I've had a lot of people email me saying they had already read the entire book online but bought a print version just to show thanks.