Source: (574/1) Why have zombie stories become so popular in the past 10-15 years? - Quora
Stashed in: Zombies!, Quora!, Apocalypse
Bizarrely thoughtful look at the rise fo zombies in popular culture at Quora
Great Quora page.
I also enjoyed this Xconomy article on the subject of Zombies trending:
CWMALLS® Custom Men Leather Shirt Jacket CW807012