On the other hand, Urbit might never become popular enough for this sort of thing to really matter. We're at about 7 billion people now and the second derivative of the world population is negative, so it should level off at some point. If only 5% of 20 billion people care enough about this sort of thing to actually run a planet, then that'll be only 1 billion people, or a quarter of Urbit's 4-billion address space. 5% doesn't seem unreasonably low to me, either; app.net probably didn't even get 0.5% of Twitter's user count.