Some new data out of Topix showing the quality (measured by post kill ratios) between registered and unregistered commenters.
Total by registered users: 22,336
Total by non-registered: 60,772
Posts by registered users that got killed: 992
Posts by unregistered users that got killed: 4,095
% posts killed (registered users): 4.4%
% posts killed (unregistered): 6.7%
The unregistered commenters have a 50% higher kill rate. But they come with 3X the traffic.
Further evidence that the Ni-Chan paradox still holds:
Registration keeps out good posters. People with lives will tend to ignore forums with a registration process. Registration lets in bad posters. Children and Internet addicts tend to have free time to go register an account and check their e-mail for the confirmation message. They will generally make your forum a waste of bandwidth. Registration attracts trolls. If someone is interested in destroying a forum, a registration process only adds to the excitement of a challenge. Trolls are not out to protect their own reputation. They seek to destroy other peoples' "reputation.. Anonymity counters vanity. On a forum where registration is required, or even where people give themselves names, a clique is developed of the elite users, and posts deal as much with who you are as what you are posting. On an anonymous forum, if you can't tell who posts what, logic will overrule vanity.
I like this dataporn since it's applicable beyond newspaper and forum sites, to other kinds of recruitment-funnel online participation systems. Make it easy for users, especially first-time visitors, to jump in and participate. But also give power users the ability to invest more in their identity on your site.