Back in 2004, a good year or so before the launch of YouTube a short piece of video known as Numa Numa went viral.  First uploaded onto newgrounds.com, in the three months following its release it was watched 2 million times on that site alone. Follow the YouTube link above and you'll see it's now logged over 25 million views in the past two years.  The full background on this story is on wikipedia.

Numa Numa is often credited as being the first viral video, however there are examples that definitely pre-date this and strangely, some of them are actually brand created. I'm specifically thinking of a series of BMW adverts for the M5 released around 2001, that's four years before YouTube hit the scene and three years before the Numa Numa phenomenon.  And back then, you really had to try hard to spread media, especially down here in New Zealand.  Broadband penetration wasn't too high and these weren't exactly small files to be emailing to your friends, but they got around nevertheless.

This one's probably my favourite and like the rest it adheres to one of the key tenets of spreadable media, put entertainment first - the product takes a back seat, well kind of.  Watch, you'll see what I mean.