My personal feelings about this series' popularity are summed up in this comic and in the hilarious book reviews by Cleolinda.
I mean, vampire romances are legion. There are lots of far better written stories out there with characters that are not TSTL (too stupid to live) abusive, shallow, and mary sue-ish. Yet, just like with Eragon, magazines went ga-ga over it (calling it the next Harry Potter? Seriously?!) and it's fans squee over it's mediocrity with frightening intensity.
Is it just because its fans have never read a good paranormal romance, or are that many people's idea of 'romance' really that screwed up? If Edward wasn't a vampire, would the reactions even be so intense? Because if you remove all the paranormal trappings (and rainbow glitter) the relationships in these books are just plain dysfunctional, and only get worse as the series goes on.
In an environment where there are so many better paranormal romantic books out there as alternatives, why is Twilight singled out at the one most worthy of all this praise? I just can't understand it.
Extra: A fun podcast about fandom in general, Twilight, relationships, feminism, and a slew of other things. =)