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.
Bought it to go over the minimum spend for free shipping however I do actually use it daily and feel it does its job. It is easy to wash off, unlike many other products which seem to need to be scraped off at times. Overall, I'm happy with it.