Glossary
What is a niche? And how narrow yours should be
The specific group of people and problems you post for.
Your niche is who you're talking to and what you help them with. "Founders" is broad, and "founders selling software to hospitals" is a niche.
Why narrow helps
When a post is written for one kind of person, that person feels it was written for them, and that's the feeling that gets a follow, a comment and a message.
How narrow
Narrow enough that the right people recognise themselves, wide enough that you won't run out of things to say. You can widen later, and starting narrow is easier.
See who's already there
Find the people already posting to your niche and look at which of their posts beat their own usual. That shows you what your future audience responds to before you write a word. Seeing what's working for creators in your niche explains how.