In the early days of the Internet, spammers primarily targeted newsgroups on USENET, the online conferencing system. These are newsgroups that are organized as forums to discuss particular topics. As electronic messaging systems advanced, it made possible the practice of cross posting - posting the exact same message to multiple newsgroups and other online forums.  

Spammers were quick to adopt cross posting as a tool of their trade. Now, they could send the same electronic message to thousands of newsgroup members at the one time. Not only could they target a larger audience with one posting, but they also did not have to differentiate between the interests and focus of the individual forums that they targeted. What's more it cost them next to nothing to spam these newsgroups. 

As email became an increasingly widespread mode of communication, the spammers shifted their focus to the massive audience that it made available to them. Mass emailing software soon became another essential tool of their trade, as they begun to use this application to send junk email to thousands upon thousands of unwilling recipients. 

The spam industry also adapted the available Internet technology to create the "spambot". A spambot is an automated program that will rove the Internet, "harvesting" email addresses from newsgroup postings and from other websites. It literally gathers thousands of email addresses in a single hour. These are compiled into bulk mailing lists with which the spammers can thousands of victims at a time.  

The practice of sending out unsolicited, unwanted junk email and junk postings came to be called "spam." The term is commonly believed to have been derived from a British comedy skit by Monty Python, in which a restaurant serves each meal with a side of spam. As a waitress emphasizes to a couple the availability of spam with every dish, a group of Viking patrons break out in song, singing "SPAM, SPAM, SPAM... lovely SPAM! wonderful SPAM!" in a loud chorus. In the 80's, the term was adopted to refer to the junk emails and postings, and the name stuck. 

The earliest, most widely known incident of commercial spamming dates back to 1994. It involved two lawyers who spammed USENET to advertise their services as immigration lawyers. They later expanded their marketing efforts to include email spam. The incident is commonly referred to as the "Green Card Spam."  

This nefarious industry has since grown in leaps and bounds. Today, more than half of the trillion-plus emails that are sent and received are spam. Initially, spam was generally advertising-related email. In more recent years, however, a particularly nasty crop of spammers has emerged, who send out their spam with nothing less than malicious and/or criminal intent. Some send out spam that contains viruses or malicious code. Others devise scams intended to defraud you of your money. And then there are those whose focus is identity theft.  

Benign or malicious, commercial or criminal - spam has transformed the way we communicate electronically, and will continue to do so well into the near future and very likely beyond. Spam has become a regular, albeit unwanted, fact of online life.