SPAM

SPAM is ANY unsolicited commercial email. The issue is commercial. As long as there is a way to make money it is SPAM, anything (such as activist emails for a cause) that does not make money for the parties involved is not by definition SPAM.

So basically, Spamming can be defined as sending unsolicited commercial e-mails (UCE). The more common term for spam is junk mail. Spammers obtain e-mail addresses by harvesting them from Usenet, bots, postings, DNS listings, and/or Web pages.

See also the post on SEOs.