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.
An excellent and very comprehensive guide to getting started in the stock photography industry. All the important issues are addressed from which agencies to upload to, what cameras to use, and most importantly, how to keyword your files. The latter being one of the critical issues in getting your images seen. Highly recommended to anyone venturing into the stock image markets.