I can understand and respect that. You just need to be clear on that a successful approach likely has to be within on standard deviation from the norm for the era in order to be successful. There are exceptions, of course. However, those typically involve very unique products.
There was an era when selling via catalogs by mail was the way to do it. Heck, even door-to-door selling of encyclopedias and vacuum cleaners was a thing. Today, that approach is at least three SD's away from the norm. In other words, it would be difficult, expensive and likely pointless.
You've put a lot of work into engineering your product. Don't waste that effort by jumping into the ocean while also trying to invent a new way to swim. Get your business solidly off the ground. You can then decide what you want from a frame of reference that includes experience and a bit of financial freedom to explore interesting options.
Another way of saying: Don't waste time. Get results. That's how you buy time and freedom to make other choices.
Alright. Let's imagine I'm already in the boat 5km from shore, and I have one day left before I'm dropped into the ocean. What should I read, watch or listen to in order to catch up on today's approach to selling, do you have some recommendations?
It really depends on where you are in this journey.
Seth Godin
Permission marketing
Tribes: We need you to lead us
All marketers are liars
This is marketing
Etc.
Ries & Trout
Positioning: The battle for your mind
The 22 Immutable Laws of Marketing
Etc.
Scientific Advertising - Claude Hopkins
https://www.foundingsales.com/
The Little Red Book of Selling - Gitomer
Perhaps others can suggest books or courses/videos on best practices for online marketing and optimization that are more up to date.
I'll warn you that at some point in my journey I hated the fact that I had more business books by my bed than engineering books. It was frustrating until I reached what I call "cruise altitude" and had enough capabilities and understanding to do well.
I never said I’m against marketing or sales. At my current stage, after building two products with the “build it and they will come” mentality, I think I understand the importance of marketing and branding way better than many other engineers.
The essence of my original comment, was pointing out the fact that from entire pose of the OP, only 1-2 paragraphs were dedicated to marketing, mainly with vague statements such as “I started to post on twitter, sometimes also jokes”.
On top of all that, marketing today is seen as beating the algorithm. And the algorithm changes every Thursday. So last week people were posting questions, today they are posting motivational quotes.
I don’t have the mental capacity, and desire, to participate in such games. I have moral principles, and I believe there is more than one way to achieve my goals. And the way I chose, might be harder and longer, but more aligned with what I want.