The Ongoing "Twilight" Obsession

Let me preface this post by saying I realize how incredibly dated this issue is - the Twilight craze has been going on for months (years? when did that first book even come out?). That being said, I'm just now giving in to the phenomenon myself and I've been thinking a lot about the whole series and amount of attention it has gotten.

Why is every girl in America so obsessed with this series?  I'm not just talking high school girls (which is the age-range of the characters in the books), I'm talking my 22-year-old, senior-in-college girlfriends.

I've asked my friends this question and their answers have varied, usually involving something along the lines of how amazing Edward (the vampire) is, and how the author has created a perfect leading male character for girls to fall in love with.  So is that really it, just extremely good character development?  Was the buzz intensified by the well-timed release of the movie and the hype of movie sequels?  Does Stephenie Meyer just have a really good publicist?

I avoided the craze for awhile but my mom got me the first book for Christmas and I got into it pretty quickly.  I can't really put my finger on what's so enthralling about the series, but I'll admit it's pretty addictive (especially further you get into the series - I'm just starting the second book).  What do you think, is there something so unique about this series that has caused such a frenzy or is the buzz just building on itself and sucking people in because they're so curious?  Why is everyone suddenly so obsessed with vampires?