How to encourage users to contribute

From the article Participation Inequality: Encouraging More Users to Contribute by Jakob Nielsen, he states "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. Often, they simply lurk in the background."

Dr Nielsen provides these figures:

• 90% of users are lurkers (i.e., read or observe, but don't contribute).
• 9% of users contribute from time to time, but other priorities dominate their time.
• 1% of users participate a lot and account for most contributions: it can seem as if they don't have lives because they often post just minutes after whatever event they're commenting on occurs.

"Although participation will always be somewhat unequal," according to Dr. Nielsen, "there are ways to better equalize it, including:"

• Make it easier to contribute. The lower the overhead, the more people will jump through the hoop. For example, Netflix lets users rate movies by clicking a star rating, which is much easier than writing a natural-language review.
• Make participation a side effect. Even better, let users participate with zero effort by making their contributions a side effect of something else they're doing.
  
• Edit, don't create. Let users build their contributions by modifying existing templates rather than creating complete entities from scratch. Editing a template is more enticing and has a gentler learning curve than facing the horror of a blank page.
  
• Reward—but don't over-reward—participants. Rewarding people for contributing will help motivate users who have lives outside the Internet, and thus will broaden your participant base.
  
• Promote quality contributors. If you display all contributions equally, then people who post only when they have something important to say will be drowned out by the torrent of material from the hyperactive 1%.