A very insightful observation from Aaron Swartz about the myth of thousands and thousands of individual users each adding a little bit of content to Wikipedia. He first mentioned the "Gang of 500" as presented by Jimbo Wales, the face of Wikipedia:
"I expected to find something like an 80-20 rule: 80% of the work being done by 20% of the users, just because that seems to come up a lot. But it's actually much, much tighter than that: it turns out over 50% of all the edits are done by just 0.7% of the users ... 524 people. ... And in fact the most active 2%, which is 1400 people, have done 73.4% of all the edits."His own research points to similarities how traditional encyclopedias work, a group of people write articles on topics they know well, while a staff formats them into a single work:
"When you put it all together, the story become clear: an outsider makes one edit to add a chunk of information, then insiders make several edits tweaking and reformatting it. In addition, insiders rack up thousands of edits doing things like changing the name of a category across the entire site -- the kind of thing only insiders deeply care about. As a result, insiders account for the vast majority of the edits. But it's the outsiders who provide nearly all of the content."