This is a recent list of promotion opportunities: https://postyourstartup.com

Good luck!

Becoming involved and contributing to my mobile app's niche on relevant subreddits. I try really hard not to be sleazy and am actively interested in the topic so I try to contribute in earnest while occasionally steering people to my app. I also setup my own subreddit where I post about my development progress during the open beta, this way if people follow it feels more like "opt-in" and gives people a chance to feedback and feel like they're properly involved during the beta period. I also have a standard landing page collecting emails, have tried throwing a few dollars at search ads but didn't really know what I was doing. HN and the other tech related sites don't do much for my specific area.

My side project is a course about Vue.js [0]. I advertise it by putting a backlink on all my free content, including blog articles/free book I wrote about Vue testing [1] and videos I upload on Vimeo, and via my Twitter.

I also joined some discord channels, and help out people with coding problems. If something in my book/course is similar, I drop a link to that (after resolving their problem).

[0] https://vuejs-course.com [1] https://lmiller1990.github.io/vue-testing-handbook/

The best way to advertise is providing some useful, valuable content for free. If people like it, they might also buy your paid content.

In the past I lucked out by people with a following finding it and linking to me. I've had less success making that happen on purpose. The thing that works for me is being consistent (posting your new music every week, etc) so that people who are true fans learn to expect you. It also took me a while to get comfortable telling people what I was working on (well, I still am getting comfortable with that). I suggest telling 10 people you know, seeing how it goes, then another 10, etc.

https://www.indiehackers.com has a ton of resources for this type of thing.

Here's is my side project:

https://medium.com/endless-filament/make-your-filament-at-ho...

I blog about the side project and share it with others who are looking to do similar things.

My side project is a blog and I use social media and SEO mostly. I also share my content to relevant groups (ie Facebook groups, Linkedin groups) and forums. I did some paid ads too, mostly od Facebook, but invested very little money so it didn't bring much traffic.

Rehashed advice, but presumably if you're solving a problem, you should know who has that problem, right? Then you go contact those people, whether through LinkedIn, cold emails, Twitter DMs, etc.

I usually post on my social channels, as well as on reddit and Hacker News to try and get some momentum.