I've sort of seen this in action. On my mailing list, current members
often bring in new members because they know the new member will make
a positive contribution.
We also have members come in from the various public places the list
is advertised, and I think a greater proportion of them are lurkers.
Anyway, before I go off on too much of a tangent, can someone point
out a place where this subject is more on-topic, or where the general
idea of Usenet problems and alternatives has been discussed?
-Danny