After watching a lecture from Matt Harding ("that guy who dances in those places in front of those things") he mentioned Attention as an important commodity. What with so many distractions now (TV shows, DVDs, Computer Games and the Internet), getting peoples attention can be a hard thing.
Viral Marketing is when an experience grabs a persons attention and makes them want to share that experience with others. After having success on the internet as "that guy who dances in those places in front of those things" he was approched by Stride Gum company to make another video. This second video he made was paid for by Stride so not only did Matt get paid for his video, he also got free global travel. This was a great way for him to sell the attention he was genrorating.
Now if only I could think of a way to get free global travel for doing something stupid!