[geoduck14]

>Well now I want to know what <niche domain> is!

Let's submit ideas! I'll start

He wanted to learn about using Machine Learning to predict how often his pet dog would need to go to the bathroom

[DonHopkins]

My cat goes to the bathroom with me all the time. He doesn't poop with me too, but he often follows me in, and we just hang out together.

[DiggyJohnson]

I believe it had to do with one of two things, I'd have to check my comments to confirm:

(1) Niche book writing software (2) Dumbphone hacking