Johan,
Usenet was developed in the late 1970s and early 1980s, about the same
time mailing lists and ecos on bbs's were developed. these were all by
different people. Usenet is best with large traffic volumes, when
typically more than 50 messages are received a day. Also, a lot of the
growth of usenet is because many mailing lists are mirrored on the usenet
system.
kelly