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.
A great product that doesn't stain my clothes and works as described. I apply once per day and armpits are still smelling 'nice' 12 hours later. Does leave some sticky residue, but its easily cleaned off with water in the shower.