These are interesting findings, Adi.
It's always refreshing to see some academic research behind what seems like something so impossible to explain, or at least irrational. Can anyone explain how a video like Gangnam Style will get viewed over 1 billion times in less than 6 months? Sure, there are elements that, put together, can spark the necessary viral components, but then things seem to have a life of their own that go beyond reasoning or marketing.
I will keep this data in mind for next time a client asks to create a viral campaign... ;-)