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.
The coffee machine makes lovely coffee. It's got a small footprint, so it was perfect for our kitchen considering we don't have much workspace. But, the coffee jug is made entirely of glass and is quite bulky to handle and so two months in, I've already managed to crack it after a gentle knock while rinsing it out over the sink - just something to be aware of!