It took me a few months to make money on my Amazon capsules. Here is what I do:
I make sure the product is closely connected to the article.
I put one small ad in the middle of the article, for one product, and explain in the title how it fits with the topic.
I put three more ads in a capsule at the end of the article.
In addition, you will discover that you will make more sales in the months leading up to Christmas.