Vampires and zombies are very popular in pop-culture these days. If you allow me to over-generalize, I'll break it down for you.
Vampires and zombies are both "undead". They are also contagious. The bite of a vampire turns a hapless human into a vampire and the same is true for the bite of a zombie.
The similarities end there.
Vampires are good-looking, romantic, brooding, highly intelligent, and possessed with superhuman strength. Chicks dig this kind of stuff.
Zombies are decayed, mindless, eating machines.
Teenage girls love vampires. Twilight and True Blood are immensely popular with the young ladies in our society. They love the idea of a handsome strong vampire sweeping them off their feet and blessing them with eternal youth.
I don't get it.
Teenage boys love zombies. There is no romance with zombies. It's just mindless killing (or unkilling). Boys love the idea of letting loose with a shotgun, shovel, or flamethrower. There are no flamethrowers in vampire movies.
I get zombies.