One of the things that I think the Sookie Stackhouse books do very well, besides appealing to women, is create a genuine small town feeling. I mean, maybe this is an area where I shouldn't really have an opinion, since the small town that I grew up in isn't really a small town by many people's standards (population of ~30,000), but it was just Christmas and I was just there and so it's on my mind.
A big part of it is how many siblings everybody has. It's not really something you notice until you start paying attention, but sibling relationships are kind of glossed over in a lot of popular culture. In Harry Potter, nobody has siblings except for Ron...that's his thing that makes him "different." In Robert Jordan (ok, maybe not popular culture), I think Matt or Perrin might have some siblings (Bode Cauthon! She has the one power), but they're mostly just a vague thought that a character might have every other book or so. In Sex and the City...I think Miranda has a sister? Buffy...three only children, until Dawn got invented. Do any of the kids on Glee have siblings?
The other half of it, I think, is age. Again with Glee...how old are those kids? I could have sworn last year was their senior year, but here they are in high school again, so I guess not. Are they all the same age? Isn't that a little unusual for an elective class? What about Ron's parents vs. Harry's parents...were they all at Hogwarts at the same time? And don't even get me started on Veronica Mars. Who's older? Lily or Duncan? Are they twins? These things matter!
In the Sookie Stackhouse books, by contrast, characters get introduced as "a few years ahead of my brother in school" or "his sister and I were on a softball team together." It stands out to me, because that's how I'm used to people talking. Sometimes, out in the big world, you feel a little self conscious about it, because isn't the biggest possible failure in life to never get past high school? Having people's family history and graduation year permanently etched on your brain feels a little odd, just as it feels odd to realize that I've met people later in life and gotten to know them well without even finding out how old they are, or being able to keep their siblings straight.
I guess there's probably room in the world for both ways. I enjoy the complex web of interconnectedness that you get when everyone comes with at least a couple of decades of personal history, which is part of the reason why I like the Sookie Stackhouse books, but I can also see how some people might find that stifling and prefer that their backstory get a little bit blurred with time. If only I could suppress my urge to provide gobs and gobs of helpful background information in every situation. People need to know these things! How can they not find them interesting?
(Also, the relationship between Sookie and Jason is one of the best brother/sister combos that I can think of. Which is of course completely dumbed down and practically ruined on the show. But then, making Lafayette and Tara cousins adds an interesting dimension, so I guess there's trade offs.)