Don:
It's either;
1)
A slice of fatty regenerated pork, which is electronically implanted into the screen on your PC, which you can see, smell - but not eat - - it drives you wild and almost insane with the desire to eat it.
This causes "drooling". The drooling then collects into a puddle on your desktop.
The puddle grows to a huge size and trickles under your computer.
The heat from the computer causes steam to rise and enters, said PC or Laptop.
This then blows your hard-drive and processor simultaneously, causing your Mother-board to catch fire and kill the computer. You as you user will not have noticed as you will still be "tonguing" the screen, until a bolt of static shock hits you, rendering you temporarily unconscious, where you will dream that you actually ate the spam.
You will awaken with a start and find you are chewing the keyboard. The spammer who sent it will be sitting in his darkened room, laughing hysterically at your misfortune!! Simple - isn't it?
OR
2)
It's unwanted, advertising usually! While you were away - someone put loads of advertising crap in this Topic!
Quickly removed - I might add!!
Wickipedia say's:
Spam is the abuse of electronic messaging systems (including most broadcast media, digital delivery systems) to send unsolicited bulk messages indiscriminately. While the most widely recognized form of spam is e-mail spam, the term is applied to similar abuses in other media: instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, online classified ads spam, mobile phone messaging spam, Internet forum spam, junk fax transmissions, social networking spam, and file sharing network spam.