A rating Web site compiles reviews to produce an average evaluation of a product, company, person, or service. The reviews are sometimes written by a team of site editors and other times by individual users. Sites such as RottenTomatoes.com, Tripadvisor.com, and RateMyProfessors.com reflect input from tens, thousands, or even millions of individual users. In order to coordinate and standardize the evaluation process, such sites often develop criteria that users apply. After a user has offered a rating or review, a conversation develops as other users add their own ratings, comments, and even responses to previous posters. Over time, this process allows for a more balanced and diverse evaluation than if only one person had provided a rating.

Some rating Web sites focus not on the quality of specific products or services, but on the degree to which a company is operated in a manner that is socially or environmentally responsible. To rate corporate responsibility, these sites typically establish a set of criteria for evaluating such characteristics as labor practices, environmental policies, international business practices, and the transparency of a company’s finances or management structure. Such ratings are intended to help consumers and other stakeholders decide whether or not to support a particular company by purchasing from or investing in the business.