Although Venkat doesn't mention them, reddit seems like the perfect example of a community that started out as a plaza, and with the introduction of user-created subreddits, evolved into a warren-like structure.<p>The article predicts that this should at least halt the "evaporative cooling" effect, as the size of the community increased. I haven't spent much time around reddit in the last few years, but is this accurate? Intuitively, it seems that separating the community by topic may also result a series of low-quality fiefdoms, where those with the most extreme views on a subject hold court.