Ask HN: Why doesn’t Amazon enforce review policies?

Everybody manipulates their reviews nowadays. Pretty much every seller asks their customers to either leave a good review or to contact support. Many contact customers who left less-than-perfect reviews and offer a refund, or a free product, in exchange for changing the review. Then, of course, there are accounts that do nothing but provide paid reviews. I’ve been contacted by Chinese merchants several times now who got my address from Alibaba purchases, and who now offered me free products in exchange for reviews on Amazon. The result of all of this is that reviews on Amazon cannot be trusted anymore. There are even online tools now that try to score products based on the quota of likely manipulated reviews. So, why is Amazon allowing this? They have all the data, IP addresses and all. Their machine learning algorithms would surely be able to figure out which reviews are real ones and which ones are fake. And yet, it seems like Amazon is quietly looking away. Wouldn’t it be in the best interest of Amazon to make sure that their customers always find the product that is really the most likely to satisfy them? Just like it is in Google’s self interest that the top search results will also be not those that are the spammiest, but those that are actually the most likely to be useful to the user?