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 gave it 4 stars as I got it for free. I'm not sure if it's the kindle layout but the writing felt like it had little rhythm and the rhyming felt strained (and occasionally just plain missed). As the title might suggest Frobilicious the Frog is not for a beginning reader to read, but the story is young child appropriate.