I wonder if PG would consider shutting down new user registration for a period of time to see what happens with traffic and submission quality.
I have a theory that the types of users that HN (or reddit in the beginning) would like to attract and keep are the very same users that show up in the first 6 to 12 months of the site's existence. After that point, it seems like all of the social network sites begin to homogenize to the digg model (in terms of quality of discourse).
A few users made their first posts more than one year after creating their accounts. Therefore, there could be a large number of dormant accounts on this forum. If you drastically limited supply then demand could encourage sales or auctions of dormant or active accounts. The market value for an account could exceed US$100 but none of it would return to the administrators. You could undercut the value and sell accounts directly to users, however this model is similar to SomethingAwful's one time fee of US$9.95, which has hardly been conducive to constructive discussion.
