I've had similar issue with my opensource tool. What I tried so far was posting at social sites where the niche users hang out. That includes Hacker News, reddi

I've had similar issue with my opensource tool. What I tried so far was posting at social sites where the niche users hang out. That includes Hacker News, reddit, twitter, various forums, slack groups, product hunt, stackoverflow, etc. I tried to do it in a meaningful way where I pointed out how my tool actually solved problems for the users in question. After that, some users decided to write blog posts about my tool, which in turn generated more traffic. In my opinion this generates quality user traffic, but isn't gonna do too much if you are looking to create a brand out of your name :(