In the past, vampires were objects of fear, but these days they are also portrayed as attractive and angsty characters, like in 'Twilight'. It's great for expressing a dual-sided charm.

'Vampire' is also used metaphorically for someone who drains others' energy, like an 'energy vampire.' It's also wittily used to refer to 'night owls' who are active at night, or to describe a dark and alluring fashion or makeup style.