Spam - Motives, Origins and Statistics

97% of all e-mails sent are junk e-mails. This astonishing figure is an indicator of the sheer waste of productivity inflicted on all Internet users. Here are some interesting statistics about Junk e-mail, also known as Unsolicited Bulk Email (UBE), commonly referred to as "spam".

SpamUnit has two excellent articles on the history of spam and present trends. From an end user's perspective, an average email address attracts 400 spam e-mails a day.

Sophos states that "Only one in 28 emails legitimate".

Spam contents, delivery and statistics are tracked and updated in near real-time by Marshal and Barracuda. See Barracuda's report on Worldwide email threat activity and Marshal's Spam Statistics.

Here's Marshal's chart on various types of Spam, as of August 2008.

And dont miss Spamhaus's reports on the worst networks, spammers and countries are below, updated monthly.
The 10 worst spam service ISPs.
The 10 worst spammers.
The 10 worst spam origin countries.

Terry Zink's Anti Spam Blog features excellent information and research and is up to date with the latest trends. His article on "How much do spammers actually make" breaks down the expenses and income for an average spam week:

Spam Sent	40 million
Click through ratio	0.12%
Total Click-throughs	48,000
Click-through-to-sales ratio	1/200
Total sales	240
Total sales revenue	$37,440.00
Spammer Commission rate	50% (Gah!)
Total spammer income	$18,720.00
Weekly costs
Bulletproof hosting	$230
4 days of botnet access	$6800
Email addresses	$4000
Total Costs	$11,030
Net Profit	$7690

A net profit of $7690 per week sounds very lucrative!