In shadow marketplaces, positive reviews for Amazon products are bought and sold. The company says it's cracking down and that it estimates that less than 1 percent of reviews are fake.

Amazon and Yelp, which have millions of reviews, finally got tired of the game, and they filed lawsuits in two states to make at least seven different websites stop selling reivews.

Thus, just as you should take all Amazon and Yelp reviews with a grain of salt, so should you take Fakespot's rating of those reviews. Algorithms can accomplish only so much.

Watch out, Yelp: Amazon has been quietly collecting local reviews for a month. by Tricia Duryee on June 11, 2014 at 4:38 pm June 14, 2014 at 11:35 am.