Why are zombies so popular these days?

For the past few years, zombies seem to have gotten more and more popular. From Thriller to any number of movies to the masks being sold for Halloween, to the number of times we are asked if we have a zombie plan yet, they have taken over the zeitgeist, in my opinion.

In addition, vampires are also very popular. The undead. The romance and sexuality of death.

What does this say about the psychology of our culture at this moment in time? What do the zombies stand for? What is the significance of zombie plans? Is it related to the economy? 9/11? The prevalence of suicide bombings all over the world?

What’s going on here?