Kevin Allocca: Why videos go viral

Memetics on TED - again:

Kevin Allocca is the "trends manager" at YouTube.

Featuring the double rainbow guy, Rebecca Black's Friday, Nyan Cat, NYC bicycle fine protest crashes and "tastemakers".

"Tastemakers" are surely usually called "influencers". Yes, influencers also influence other things - besides taste - but I'm not sure about whether there is much need for this proposed terminology.