Other people have done a lot to help at their own initiative though. Resellers approach me and market it themselves, customers recommend it on forums, researchers mention it in their published papers, and one customer even wrote a chapter of a book about it - which was key to being eligible for a Wikipedia page.
I'm lucky though because it belongs to a slow moving, well-defined class of products that people in my target industry already understand so when they go looking for a cheaper alternative to the super-priced big names, they find mine. I'm not inventing a new market.
It's not free money though. It's very code-heavy and technical-understanding-heavy and I've spent nearly 20 years actively developing it by now. One man wouldn't be able to just smash one out in a year, and you'd need some reasonably deep domain knowledge.