As a sequel to Mark Martinec's "Google trends" survey of a while
ago, here is a contemporary survey by a company that was looking
for leads for their sales department.
Instead of scanning the IP address space and ending up with lots
of tiny dekstop boxes, or scanning the DNS and ending up with lots
of bogus domains, they worked from a list of 400000 real companies
(they were looking for sales leads, after all).
Surprise: the result is not all that different from Mark's. The
slide below, based on an article in O'Reilly SysAdmin, is part of
an invited talk that I gave at CEAS 2007 last week.
Wietse
http://www.porcupine.org/postfix-mirror/postfix-mailchannels.pdf
