It should be noted that the film adaptation of the novels by Meyer was not the first movie about vampires in history. As for literature, the novel by Bram Stoker's "Dracula" was published in 1897. About Dracula and was the first movie in the first half of the XX century. Since then shot several dozen themed films. Many people remember the film adaptation of Anne Rice's novels - "Interview with the Vampire" (1994, Tom Cruise and Brad Pitt in the lead roles) and "Queen of the Damned" (2002) as the highest quality.
What is the popularity of the "vampire" theme? Firstly, it is the dream of eternal life, living in the mind of many people. I'm wondering what it is - see the change of times and still young, do whatever you want. Especially popular topic among girls. This is probably due to the fact that most of the heroes of novels about vampires are attractive young men. They are in the books by Anne Rice and Stephenie Meyer's books.
Second, in their role as selected attractive (from the point of view of the majority), the actors who appear in the role of "perverse romantic." And contrasts attract attention. These characters are evil in themselves, but often at the same time distinguished nobility, refinement of manners, education, the plot often come from aristocratic circles. They are strong, fast and tough, their abilities far surpass the common people. They are timeless and will always remain in their prime. In the minds might get a perfect image.
Perhaps the role played by the presence in the books and movies love interest, without which they are likely to have been less popular. Romance in conjunction with the mystery and danger - a sure way to gather a large audience.