We simply can't include every webcomic in the world. To avoid people
using Wikipedia as a promotional vehicle we have to use inclusion
guidelines to keep in stuff that deserves an article - highly popular
(verifiably so) webcomics with a not so small run - and stuff that
doesn't deserve an article - your average Joe site with 4 comics, a
dead forum and no Google or Alexa rank because they don't have
visitors.
Of course, Google and Alexa aren't everything, but if those can't be
gauged to determine a comic's audience, we need the author to provide
the information by other means. If the audience can't be verified it
doesn't belong on Wikipedia.
We don't include unremarkable people, forums or ads for businesses.
Webcomics should be no different.
How popular a comic needs to be and how many visitors it needs to
attract is, of course, up for discussion.
----
Example: We had several webcomics with bad Alexa ranking and dead
forums. Someone complained that the forum recently moved. How are we
supposed to know if they don't tell it or provide sources for the
article. Any edit window asks people to cite sources, yet people fail
to do so far too often...
--Mgm