Have you ever wondered why your Google star rating is lower than the average of your individual review ratings? For example, you may have an average star rating of 4.8 on Google, but have only 5-star reviews. How is this possible?
The answer is that Google is not calculating a true average of your review ratings. On their help page, Google states “We calculate an overall rating based on user ratings and a variety of other signals to ensure that the overall score best reflects the quality of the establishment.”
What does this mean?
Mike Blumenthal, Google My Business and Local Search guru, explains:
“Google clearly is weighting 5-star reviews differently if there are less than a certain number and they are probably using an algorithm that is something like a Bayesian average. In other words, when you have a very small sample (i.e. few reviews), Google is using its large dataset of review stars to model and estimate what your average would be IF you had more reviews. All very Googly, as they say.”
There is not much that businesses can do to combat this algorithm. According to Blumenthal,
“…You just need to keep at the project of providing great service AND encouraging your clients to leave reviews. Sooner or later (20, 30, 40 reviews later?) Google will calculate a real average for you.”