Some common uses of these systems can be found on E-commerce websites such as eBay, Amazon.com, and Etsy as well as online advice communities such as Stack Exchange.
[1] These reputation systems represent a significant trend in "decision support for Internet mediated service provisions".
The role of reputation systems, in contrast, is to gather a collective opinion in order to build trust between users of an online community.
Howard Rheingold states that online reputation systems are "computer-based technologies that make it possible to manipulate in new and powerful ways an old and essential human trait".
[3] Rheingold says that these systems arose as a result of the need for Internet users to gain trust in the individuals they transact with online.
Paul Resnick from the Association for Computing Machinery describes three properties that are necessary for reputation systems to operate effectively.
User feedback in reputation systems, whether it be in the form of comments, ratings, or recommendations, is a valuable piece of information.
Other pitfalls to effective reputation systems described by A. Josang et al. include change of identities and discrimination.
[6] It was originally aimed at email applications, but it was subsequently developed as a general architecture for a reputation-based service, followed by an email-specific part.
For example, a wide range of studies have found a positive correlation between seller rating and selling price on eBay,[10] indicating that high reputation can help users obtain more money for their items.