To calculate the overall star rating and percentage breakdown by star, we do not use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
Works like magic, but beware of overuse. Your skin can get used to the product, so either take a break from using it once in a while or alternate with another product. I learned it the hard way and my acne broke out again. I'm a guy btw.