Security researchers around the world are giving a tongue-in-cheek salute to the 30th anniversary of the first spam message.

Gary Theurk, an employee at Digital Equipment Company, sent a message on Arpanet to hundreds of fellow users on 1 May 1978.

The message advertised the latest DEC computer systems, and received a less than enthusiastic reaction from fellow users.

Arpanet has since evolved into the modern day internet, and DEC was purchased by Compaq and later HP.

Security firm Sophos noted recently that some 10 per cent of respondents to a recent survey admitted to purchasing spammed products.

"If users didn't buy the goods, or invest in the pump and dump stock, spam would soon dry up," said Mark Harris, director of Sophos Labs.

"The spammers wouldn't make any money from their activities and would go out of business."

Sophos has launched a Spam Pledge in a bid to stamp out the scourge of spam.