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.
These books suck you in. In many ways they are like family with all those irritating relatives, favourite aunts and uncles and pain in the arse siblings. Love them, hate them you can't help but stick with them. Love the series, wish there could be more.