All modern social networking and aggregator marketing that isn't ad-slot purchased, astroturfing, or some variation can be summed up as:
When your project is relevant to discussion, share it.
For example, I publish a niche product. The largest pure Lua game engine on the market. When people talk about game engines, usually 2D game engines, or multiplayer networking, I usually talk about Planimeter Game Engine 2D.[1]
Since ours is one of the few game engines (period) on the market that ships, out of the box, with full client-side prediction and reconciliation without a developer having to write their own networking code, and that's a pretty big deal for young or hobbyist developers, it's pretty easy to see why you might want to consider Planimeter's software instead.
Does Godot do that? No. Does Unity? No. Did you know that even Unreal Engine 5.1 has unreliable player movement out of the box? Yep. You're on your own with all three of the major game engines that are typically discussed. None of them do multiplayer client-side prediction for you, or in Unreal's case, they don't care if it's unreliable and your player jumps around everywhere--by design. Seriously.
None of those guys care at all about multiplayer. What they care about is marketing their photorealistic rendering pipelines. Except young hobbyist developers don't publish photorealistic games. They want to publish multiplayer games they can play with their friends.
And because there are so many pieces of game software out there, and there are larger competitors by two orders of magnitude above our offerings, I usually have to bring up our product more often to share alternatives with people.
The key is finding relevant times to share, versus spamming. Share when you release updates, share during discussions, go to places talking about the topic you're writing for.
See? Just like that. There was a topic at hand, marketing, I shared my experience with you, it was relevant, I didn't buy an ad slot, and hopefully you got something out of it.
I submitted the project on various places: HN, Reddit, Product Hunt, and lots of directories like Beta Page. HN was the best, by far. Lots of interesting feedback. Reddit was okay, but you need to post at the right time of the day, and present your project so it doesn't look like an ad (like "I created X using Y framework, feedback welcomed"). Still it helped, but it really depends on the sub on which you are posting. Product Hunt was average, Mockoon wasn't at the top during the day, more like no. 4 or 5, just under the fold. And all the directories helped only for the SEO. They didn't bring any significant traffic.
After the launch, I started writing articles, tutorials, having a good readme file on GitHub (it's an open-source project), make sure things are cross-linked and polished (the Docker image page, the NPM page, etc.). Today, the primary source of new users is word of mouth and SEO.
I have a Discord, Twitter and LinkedIn page, but I am rather bad at creating a community. Also, it requires posting very frequently about anything and everything which is time consuming with very random results. Sometimes I post an update on what I am working on, and I get 10 likes, sometimes 0. Very frustrating. Then, the post is lost forever. LinkedIn is showing way better results for me though. I would say invest in SEO. It is a long term game, you still depends on Google, but if you do things correctly it pays.
This next one might not stand the test of time given that Mastodon is still finding its place in the social media landscape, but right now, Mastodon is a great place to share and build interest in both your paid and free open source projects. The culture is very much open to promotion of "cool stuff you're working on", unlike the majority of established social media platforms.
If you're working on something that is quite visual, it's worth looking into TikTok videos as well. There are more than a few pieces of software that I've been turned on to by repeated exposure through TikTok.
Look for new platforms and communities that are not sick of things being promoted. There is an excellent observation about Mastodon now in the comments.
SEO works. I've prototyped a new project recently – a collection of learning resources on IT topics (https://bestresourcestolearnx.com) – I haven't even started to promote it yet but it gets some relevant SEO traffic anyway.
Creative promotion ideas are project-specific, but I would think about how you can collaborate with people with some audience in your field. Like game developers giving away their games to streamers and influencers.
And mention your project when the opportunity arises (if appropriate, of course).
I can't say I've had a lot of success. Most posts on Reddit get removed as ads and relevant Discords tolerate self-promotion even less. Got one upvote from HN [1] though. Perhaps if I'd written it in Rust instead of C, it might have done better here :)
He also authored a book entitled "Traction: How Any Startup Can Achieve Explosive Customer Growth".
Video can get some exposure, though it is more work than a blog post.
- My blog
- My project's blog
- Facebook groups
- Old school forums
- Discord/Slack
Note that posting something once isn't nearly enough marketing.