Jacob Nielsen, in his usual stellar style, has published an excellent article, on participation inequality in Internet communities:

User participation often more or less follows a 90-9-1 rule:

• 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.

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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.

Here is a shameless plug for our older post of the size of blogosphere (Jacob Nielsen’s numbers match pretty well with our numbers).

Some of the participation inequality is driven by inherent human nature. As a result even physical communities display lop-sided participation characteristics. Internet, though, I think exacerbates this problem. Following are some of the reasons:

• People are inherently selfish. Contributing to a community does not come naturally to most people unless there is a reward associated with contributing. The mechanisms for providing reward for participation are largely missing from the web at this point in time.
• The default substrate for interactions on the Internet is anonymity. It takes an extra effort to get them to drop the cloak of anonymity and express their opinions. This happens only when they feel really-strongly about the topic of discussion.
• Bad UI design that discourages users from participating. One of the most annoying issues here is requiring users to register before they can leave a comment.
• Read-only web interactions used to be the norm for most web 1.0 interactions. We are just starting to focus on the community participation and user generated content etc. and I suspect over time these statistics will change for lesser inequality.

Jacob Nielsen focuses on the effects of participation inequality on the web:

• Customer feedback. If your company looks to Web postings for customer feedback on its products and services, you’re getting an unrepresentative sample.
• Reviews. Similarly, if you’re a consumer trying to find out which restaurant to patronize or what books to buy, online reviews represent only a tiny minority of the people who have experiences with those products and services.
• Politics. If a party nominates a candidate supported by the “netroots,” it will almost certainly lose because such candidates’ positions will be too extreme to appeal to mainstream voters. Postings on political blogs come from less than 0.1% of voters, most of whom are hardcore leftists (for Democrats) or rightists (for Republicans).
• Search. Search engine results pages (SERP) are mainly sorted based on how many other sites link to each destination. When 0.1% of users do most of the linking, we risk having search relevance get ever more out of whack with what’s useful for the remaining 99.9% of users. Search engines need to rely more on behavioral data gathered across samples that better represent users, which is why they are building Internet access services.
• Signal-to-noise ratio. Discussion groups drown in flames and low-quality postings, making it hard to identify the gems. Many users stop reading comments because they don’t have time to wade through the swamp of postings from people with little to say.

He also goes into what can be done to address the situation somewhat:

• 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. For example, Amazon’s “people who bought this book, bought these other books” recommendations are a side effect of people buying books. You don’t have to do anything special to have your book preferences entered into the system. Will Hill coined the term read wear for this type of effect: the simple activity of reading (or using) something will “wear” it down and thus leave its marks — just like a cookbook will automatically fall open to the recipe you prepare the most.
• 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. In avatar-based systems like Second Life, for example, most users modify standard-issue avatars rather than create their own.
• 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. Although money is always good, you can also give contributors preferential treatment (such as discounts or advance notice of new stuff), or even just put gold stars on their profiles. But don’t give too much to the most active participants, or you’ll simply encourage them to dominate the system even more.
• 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%. Instead, give extra prominence to good contributions and to contributions from people who’ve proven their value, as indicated by their reputation ranking.

I couldn’t agree with him more…Providing the right incentives to participants is the key to cracking this tough nut.