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'm left torn between shaking my head in disbelief that people could really act in such ways and laughing my head off! Good stories, well written, and basically clean, this is one I'll be coming back to when I need a good laugh. Highly recommended.