That's a really interesting snapshot of 1990s nettiquette. On Usenet or Email you generally selected a pithy quote for your email footer. The trend went out of fashion I'd say around the turn of the century.
It does when the mailing public stopped using Unix and mail programs that were smart enough to shell out to external programs to compute the signature. Now we have webmail where only one company decides what programs you cannise to compose mail.
