I had zero problems acquiring first 1K customers for my product. Just spammed some relevant forums. Actually I got way more then 1K this way. Problem was that said amount was not making it worth for me. And acquiring more presented a challenge. Basically lacking external investment to increase market share by whatever means I put that particular product on a diet (invest few hours here and there). Since then it brings me small but steady income without investing much. As I have other products and also create those for other companies I am ok and happy with what I got for my efforts. But if I had to live from that single product it would not be a comfy life to say it mildly
I did not comment on every thread. But I do answer some relevant questions on forums where my answer is likely to be appreciated and my signature is linked. Sometimes write short semi-article in the post (same thing with the signature). Also do product announcement once per forum. Sometimes they have rules against it but they also often let it slide. At some point was noticed by some reviewers and that had some positive outcome as well.
But as already said nothing really stellar in that particular product I mentioned
