Another notable quote:
The normal experience of social software is failure. If you go into Yahoo groups and you map out the subscriptions, it is, unsurprisingly, a power law. There's a small number of highly populated groups, a moderate number of moderately populated groups, and this long, flat tail of failure. And the failure is inevitably more than 50% of the total mailing lists in any category. So it's not like a cake recipe. There's nothing you can do to make it come out right every time.
We can observe the phenomenon on any IBs that allows to see the number of users per board.
But I believe successes and failures should be viewed more shaded. For example a themed board can easily out of league compared to an "everything can go" board. The overwhelming majority of 4chan's boards cannot compare to it's /b/, only certain topics, like gaming can only compete there.
A twist of fate shows otherwise on End, where communities settle and they rarely roam about to other baords, they have their own interests and they are here for that. They could visit /b/ but not many do.