• Participation Inequality: Lurkers vs. Contributors in Internet Communities (Jakob Nielsen's Alertbox)
  
  In most online communities, 90% of users are lurkers who never contribute, 9% of users contribute a little, and 1% of users account for almost all the action.
  90-10 90-9-1 content discussion groups inequality networking pareto participation principle social user-contributed weblogs
  in Public bookmarks with community research socialnetworks by 4 users
• The Physics of Friendship
  
  PhysOrg news: The Physics of Friendship
  friendship physics research science technology the
  in Public bookmarks with socialnetworks socialsystems by 2 users

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