[noonespecial]

Your * is very insightful. Implicit in my suggestion is the fact that the service is able to count how often you use it vs your +ve and -ve reviews.

When I say "seldom" I of course mean "uses the service often, but seldom complains". The unit of time in this exponential weighting is not chronological, but uses of the service.

This of course is harder with yelp than uber.