After reading, I've understood the cause of "Twilight boom". I'm convinced that this book was written for young girl's.
In Japan, there are some famous idol groups who girls get crazy. And this boom is spreading to Asian countries, like Korea or Taiwan or Veit nam. I think that such a generation, adolescent children need something that fasionates them. But in US, untill now, there was no idol who young girls get crazy.
There are all kinds of items which fasinate girls, danger and handsome boy and endless love and forbidden love with this book.
The story begins with the heroine's move, to a bit mysterious town. Her name is Bella. She meets with a boy, incredibly good-looking, and she falls in love with him. But in fact he was a vampire. She was an ordinary girl in former town, but in this mysterious town, she suddenly becomes popular. This is a dream of every ordinary girl.
This story is written from Bella'spoint of view. So, as reading, girls would identify theirselves with Bella and they might feel to fall in love with him.
Interestingly, "Twilight" is really leaving from the real world. Girls would realize "this is just a story". So, this boom may not last for a long time, like a Japanes idol phenomenon.
And I'm looking forward to seeing what the last scene will come.