Is My Book Simply Too Niche?

I published my first collection of poetry in late summer. It sold okay for the first couple of months, probably mostly due to family and friends buying it. But I’ve only sold one copy in the last 30 days.

I’ve tried changing my keywords, but it hasn’t made a difference. Poetry itself is a niche, and my book is a collection of Christian poetry inspired by The Divine Comedy, so I’m wondering if my book is simply too niche.

My first keyword strategy was to tie my book to The Divine Comedy and hope people searching for The Divine Comedy might decide to give my book a chance as well. I’ve changed the keywords recently, but there wasn’t really strategy behind it, other than using keywords that I felt were accurate to my book.

I’ve gotten a few organic sales that left very positive reviews, so I don’t think it’s a question of my book’s quality. I’m not really sure what to do at this point. I’ve thought about maybe spending a little bit of money on Amazon ads, but other than that I don’t have any ideas.

If anyone has any advice, I would greatly appreciate it.

Here’s the link to my book for anyone interested: https://www.amazon.com/dp/1738249115