Of all of the things that people do online, the act of offering an opinion is not only one of the most popular activities, but it also underpins almost everything else that happens. Sharing opinions is also the foundation for creating communities, whether that is around blogs, news, social networks or e-commerce sites.
Very early on, some sites recognised that opinions would carry much more weight if there was some way of increasing the level of trust between those offering the opinion and those seeking it. In the “real” world, this is normally done through a person having earned a reputation. Review sites like Yelp for example, signal the reputation of reviewers by listing the number of connections they have on the site, how many reviews they have done and most importantly, whether they have earned an “elite” status.
Technological question and answer site Stack Overflow explicitly awards reputation points to those asking or answering questions that get “upvoted”. Only people with a certain reputation are allowed to upvote and so the system allows people to very quickly filter relevant questions but also the answer that the most trustworthy people, thought was best.
What Stack Overflow has done is establish an extremely effective “reputation system“ that allows everyone to be able to quickly assess the quality of an opinion or review expressed by users of that site.
Sites like eBay used the mutual rating of buyers and sellers to establish enough trust to enable transactions to happen between unknown people online. This in turn allowed companies like Airbnb and Uber to also be able to establish trust in the physical world through reputation managed online.
Without trust between a host and guest, Airbnb would not be able to function. Somewhat differently from eBay however, reputation on Airbnb comes from the company allowing host and guest to review each other and for this information to be publicly available.
