It’s different every time, but basically “marketing”. No matter where you are showing your stuff, it’s in a subset of the population, chances are HN won’t be buying your app subscription. You need to get it in front of your actual audience.
See also "Product Hunt". Oddly it's been about a year since I've noticed anybody who mistakes a Product Hunt launch for a marketing plan but that used to be endemic.
As someone who has a small bit of skill in marketing nowadays, where would you advice me to deeply learn it? I think I have enough knowledge now to have developed a taste of what is actually good but don't know where to find a good curriculum to get started.