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.
I would recommend this to everyone, let me tell you my experience. It started like any other day except this day I had put my trust in Rexona Clinical Protection - Clean Scent to remedy my overly manly musk/odour. And boy it did not disappoint despite me pushing it to it's limits even after a whole day out and about and vigorous sex with the Misses the next Morning she woke up with her head in my armpit and complimented me on my scent!