You can sell and promote every single item on the Amazon website but it is always ideal to keep the things you promote related to your blog topic.

If your blog is about a hobby (like fishing, gardening, golf), it’s best to promote products that are related to that topic. it would be weird and confusing if your blog is about fishing and you’re promoting baby clothes right?

However, if you happen to mention a product in a blog post and it’s not really related to your niche, there is no harm in linking to it on Amazon if you think it people will be interested in it. Just don’t make it the point of your promotion.