Amazon's Book Category is used to merge variations with reviews of shared unrelated products.

There is an anomaly in their comments. The content of their comments consists of 2 parts:

1) Reviews on U.S. sites are direct customer reviews (unverified purchases). But the time of the comments is the same day. This must have been a third-party agency that used a large number of buyer accounts to reviews.

2) These products share irrelevant reviews from Japanese sites. Sellers exploit a vulnerability in Amazon's system by merging variations by using book categories, enabling these products to share reviews, and to split the variants but not the shared reviews.

All in all, Amazon has a very serious review sharing problem. Especially in the book category. Because of this category, sellers don't need brand consistency in merging variants, and they don't need category consistency to merge variations.

ASIN(s) : B0F43N25FJ, B0FF2575BG, B0F4NG5VN3, B0FF92TRXB, B0F4NJ34MY

URL(s):

https://www.amazon.com/dp/B0F43N25FJ

https://www.amazon.com/dp/B0FF2575BG

https://www.amazon.com/dp/B0F4NG5VN3

https://www.amazon.com/dp/B0FF92TRXB

https://www.amazon.com/dp/B0F4NJ34MY