These "grass roots" recommendations require little site-directed effort, since the customers do all of the evaluation. They also
provide a high degree of credibility since customers often are more likely to believe a set of other customers than the marketer who
makes money on the purchases. As a side benefit, they create a sense of community that can distinguish the site from others and
thereby retain customers. Customer comment applications provide a summary of the ratings, either as an average or another figure
representing the rate of positive and negative recommendations, and give the customer an opportunity to read through the ratings and
form her own opinion.