Many people, specially my age(which, by the way, is 17), think that the "vampire craze" started as a result of the Twilight series (that's what initially got me interested in vampires, true, but that's just because I was very ignorant when it came to fantasy fiction; a thing I regret). Vampire myths and folklore are, actually, as old as the human civilization itself. Vampire fiction is rooted in the 'vampire craze' of the 1720s and 1730s; when the vampires were quite unlike today's vampires.
Why these myths first came to be, can be explained by the natural, but in those days inexplicable, processes of death and decomposition. People often suspected vampirism when the body did not look decomposed; as the gases from decomposition caused the torso of the body to swell, making it look well-fed. This body, when staked, would deflate with a groan-like noise, as the gases escaped. The idea that vampires can only be killed with a wooden stake through the heart, however, is a mere co-incidence; as the dead body, which was assumed to be a vampire, was in a cemetery close to a church; and the priest happened to stake the body with a wooden cross, right through the heart(which "killed" the vampire, effectively). This also explains a vampire's fear of the cross. Also, after death, skin and gums lose fluids and contract, exposing roots nails and roots and parts of teeth that were concealed inside the jaw; which were mistaken as sharp, claw-like nails, and fangs. Porphyria is a rare blood disorder, often confused with vampirism, where the skin of the sufferers is affected in directed contact with sunlight - making them synonymous to the "Creatures of the Night". Rabies has also been linked to vampirism; a disease which can cause a drive to bite others and a bloody frothing at the mouth. Of course, these myths were fueled by regular sightings of dead family members and lovers at night, which were probably just hallucinations.
From James Rymer's Varney the Vampire, ofcourse, to Dracula by Bram Stoker and Carmilla by Joseph Sheridan le Fanu, to the Vampire Chronicles by Anne Rice and Salem's Lot by Stephen King, till the recent Vampire Diaries by LJ Smith and of course, the Twilight series by Stephanie Meyer; vampires continued to captivate us, soon becoming not only terrifying, but also highly attractive and alluring.
It is safe to say, of course, that Twilight is not one of the best books about vampires. I wouldn't even call it a great book otherwise, vampires or no vampires; but since I'm discussing vampires right now, let's leave aside the too much use of adjectives, too many repetitions, too shallow/predictable characters, and basically the fact that they are four books of nothing, really. So when you are bad at all these things, you could at least get your facts right; i.e vampires don't sparkle, vampires have fangs et al. And, finally, if you can't do that either, come up with your own story!! But no, Twilight has everything from Charlaine Harris's motorcycle gang of werewolves, to LJ Smith's, well, kind of the whole same story, and also Edward Cullen: Twilight's very own, rather badly copied version of Joss Whedon's Angel: the good vampire who ran around saving people's lives, the messy hair, the handsome, pale face, the falling in love with a human girl, all of it, and, not to mention, the fact that Meyer keeps calling him "angel". It is also copied, apparently almost scene to scene from a book called The Nocturne by Jordan Smith: I haven't read the book myself, but this was enough to convince me. And it has still sold around 100 million copies worldwide. Of course, in a world where people like Miley Cyrus become famous singers, Stephanie Meyer was bound to get lucky.
What I am concerned with is how Stephanie Meyer has single-handedly destroyed the entire vampire genre. The world isn't divided into people who like vampires and smart/sensible people. People who like vampires are not necessarily crazy teenagers who are obsessed with Twilight. Twilight vampires are not real (or precise: because vampires aren't real anyway!).