There are certain types of books that I more or less assume all readers read. (Novels, for example.)
But then there are books that only YOU read. Instructional manuals for fly-fishing. How-to books for spinning yarn. How to cook the perfect souffle. Rebuilding car engines in three easy steps. Dog training for dummies. Rewiring your house without electrocuting yourself. Tips on how to build a NASCAR course in your backyard. Stuff like that.
What niche books do YOU read?
I had a harder time with this question, I'm not sure I really have a niche. I'll stop at browse at anything that grabs my eye but usually just stick to my normal reading genre. There are some books I can't resist but wouldn't necessarily think they are a niche.