I love the idea but whenever I look in these it’s always the weirdest books and never anything I’ve heard of

I guess that is expected though as the unwanted ones build up over time

I feel like they are often unwanted discards... but we have one and we try to put interesting books in there. Recently gave away my entire Harry Potter series.

Sorry. I'm the weird niche author who puts a copy of his books in these whenever I come across a new one. Author's copies are so bloody cheap and little free libraries are full of weird stuff already, it feels more likely someone looking for books in one will appreciate mine.

Why would you want something you'd already heard of? That's hardly a discovery you could get such a book at the public library.

The ones in my neighborhood are full of religious evangelism titles or bad self-help books.

Consider stepping out of your comfort zone.