All large-scale, multi-user communities and online social networks that rely on users to contribute content or build services share one property: most users don't participate very much. In contrast, a tiny minority of users usually accounts for a disproportionately large amount of the content and other system activity.
This phenomenon of participation inequality was first studied in depth by Will Hill in the early '90s, when he worked down the hall from me at Bell Communications Research.
Before the web, researchers documented participation inequality in media such as Usenet newsgroups, Compu Serve bulletin boards, Internet mailing lists, and internal discussion boards in big companies.
A study of more than 2 million messages on Usenet found that 27% of the postings were from people who posted only a single message.
Conversely, the most active 3% of posters contributed 25% of the messages.
In Whittaker et al.'s Usenet study, a randomly selected posting was equally likely to come from one of the 580,000 low-frequency contributors or one of the 19,000 high-frequency contributors.
There are about 1.1 billion Internet users, yet only 55 million users (5%) have weblogs according to Technorati.Worse, there are only 1.6 million postings per day; because some people post multiple times per day, only 0.1% of users post daily.Blogs have even worse participation inequality than is evident in the 90–9–1 rule that characterizes most online communities. Inequalities are also found on Wikipedia, where more than 99% of users are lurkers. Wikipedia's most active 1,000 people — 0.003% of its users — contribute about two-thirds of the site's edits.According to Wikipedia's "about" page, it has only 68,000 active contributors, which is 0.2% of the 32 million unique visitors it has in the U. Wikipedia is thus even more skewed than blogs, with a 99.8–0.2–0.003 rule.Participation inequality exists in many places on the web.A quick glance at Amazon.com, for example, showed that the site had sold thousands of copies of a book that had only 12 reviews, meaning that less than 1% of customers contribute reviews.