Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Great for this price. Dries quickly and decently long-lasting. On close-up inspection the line seems slightly less smooth than I've have liked, like there's very minor clumping, but it could be my technique. The general effect is still decent, and I'd buy it again.