Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
Although cute they certainly are not worth the price. Some of mine wouldn’t stick once placed and when I checked out the gift I had placed them on they had started to come up. For one sheets of stickers you’re better off looking elsewhere.