This is Spam. What? Need more? Okay fine...
Spam² - A horrible tasting, ham substitute that is widely popular in Hawaii. Also believed to be a parrot deterrent
Spam³ - The posting of substance material that has little or nothing to do with the original topic being discussed. Usually annoying in nature, "spamming" has been known to lead to loss of the game, a sudden spike of awesomness of a certain topic, flame wars and the occasional British Invasion. "Spam Threads" have been used to express a communities extreme dislike of certain things as well as a safe way to release over-accumulated boredom.
So now you know what it is. Now go! Stop reading and DO IT
*It should be noted that spamming in a "Spam Thread" is technically impossible, as posting of un-related material is in fact the point.