It has had quite an effect of zombie culture. It's portrayal of the undead as rabid killing machines has spread to become the template for the species, and the book's signature, the Lobotomiser, is widely accepted by the zombie-killer community. It is a must read for all fans of the living dead, for all lovers of subtext, and for all people who enjoy a good horror story.
It was loosely adapted into a 2013 movie starring Brad Pitt.
Also, the movie of World War Z is totally watchable, if a little castrated for gore.