Amazon's Reviewer Formula

by Jeffrey M. Welch

I have been collecting data that accompanies my reviewer rating on Amazon. It is not actually obvious how each part of your activity on Amazon impacts your rating overall. It is pretty well known that the following items are part of the calculation in no particular order:
  • Total number of reviews
  • Quality of reviews (based on helpful/not helpfuls ratio and total number)
  • Total number of helpfuls
  • Total number of unhelpfuls
  • How recent are your reviews, more recent definitely moves you up in the ranking
  • Comments from users and your interaction with them are also likely a piece of the puzzle

What isn't clear is how each is weighted. The following two seem to be the most important:
  • How recent your interactions/reviews/helpfuls are
  • The total number of helpfuls combined with your helpful/not helpful ratio

I intend to collect more data over time in an effort to understand this formula better, but it is pretty clear that there is a lot of math, and not all of the data that you need to compute a formula is available to the public. So the complete formula will almost certainly remain a mystery, if not a constantly moving object.

As I collect more data and begin to analyze it in depth I will attempt a rough guess at how the formula is calculated. I hope to get close!

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