For the most part, we recommend to not purchase items that do not have a main category on Amazon. This means that the item doesn’t sell enough to register in one of the main selling categories. It is usually best to move on from this item and find another.
To get a sense for how much a product like this sells, you could try the manual method as outlined in the Product Research in Depth module of the course and the blog below:
Popular "Sub Categories" that would require this approach include; Amazon Launchpad