I have heard a lot of success stories but would love to hear from you guys
Here’s some advice in no particular order:
There’s no such thing as passive income, you will need to put in a ton of initial effort.
Make sure your product has minimal upkeep. Build once, sell many.
Listen to your users.
Know when to listen and ignore feedback.
Solve a problem that exists.
On the internet a small piece of the pie is big enough. Be small, Be great.
Respect the user. Don’t track them or do other shady things.
Or so a moralistic idea goes. I doubt most founders of nonetheless succesful companies are "passionate" about sewage disposal or other things, and I've known several owners of sucessful companies who are hardly passionate about the product, but are very passionate about selling it...