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.
Good story. I'm amazed at the writer's ability to make up stories with so much detail. It was all a bit slow for me, I like a bit faster pace. But Spence was great at asking questions and organising his team to get information. It's just that in the end I felt I hardly knew Spence st all. I knew some of the characters he was interviewing better than him. So by the end of the book I had no desire to read another one because I didn't sort of get to know him for better or worse.