Stop focusing on the big launch
A lot of people put too much weight on launching their products on Product Hunt and the like.
The truth of the matter is that those launches are very ephemeral. Think of the news cycle. News stations rely heavily on a lot of new things happening and that's what they push on that day.
The same thing happens for products, unless of course it's a product that will get lots and lots and lots of people engaging with it.
But for most profitable online businesses, you shouldn't really focus on the big launch. You need to always be launching, finding new ways for you to get value out there in front of your audience. Think of it as micro-launches instead.
What happens after the launch is it teeters off, and growth is pretty much non-existant, unless you think about the organic growth opportunities afterwards.