Zombies may be the walking undead, but their contribution to Main Street’s economy is very much alive. In modern times, the zombie genre has evolved from a cult following to a highly popular theme. 24/7 Wall St. estimates that the today’s zombie genre economy is worth billions of dollars. Think way beyond zombie movie ticket sales. Think about DVD sales, video games, comic books ... And if you think the financial tab has been high so far, by the end of 2012 the tab is going to be far larger.