Kevin Allocca is the "trends manager" at YouTube, which means, as he says, he watches YouTube videos for a living -- and then thinks about why they become popular. In this TED Talk, Allocca runs through a series of viral video hits and attempts to explain why they became popular. While it's not exactly deep thought (it seems to boil down to "new media is awesome!"), his discussion of Nyan Cat and videos of other cats watching it is worth the price of admission. Have a look: