The first spam message was sent on Arpanet (what would become the Internet) on 3 May 1978 from Gary Thuerk to his mailing list of 393 people with the aim of promoting a new computer from Digital Equipment Corporation, a company no longer in existence.

The practice was rapidly adopted, as the spam message from Thuerk succeeded in selling one or two computers, which encouraged people to continue spamming in an effort to make some sales. That very motive is still strong today and there is a good reason for it. A spammer can make up to $7000 in a single day, according to a study conducted by the University of California at San Diego in 2011.

The first chain spam appeared in 1988, while the first major spam issue, Green Card spam, hit the Internet in 1994. The Green Card spam was sent from lawyers who claimed to help people get a Green Card for a small fee, but in fact the application process for a Green Card is free and quite straightforward.

Thuerk’s spam message grew from something that was an irritation for less than 400 people on an Internet forerunner network into a global headache for millions, draining over 70% of the bandwidth consumed by e-mail.

Although that figure might sound daunting, spam traffic has been decreasing lately as a result of several factors. Law enforcement agencies are now tougher on spammers. Spam filters now have improved functionality and block these messages. And spam fighters have taken down some larger networks that were spreading the digital junk.