Cathy Clark says many of those books - targeted at teens - also attract adult readers like her.

"You have those really strong authors in Young Adult and no matter what your age [is] they appeal and paranormal is something different," she said.

Meet the authors

Some 70 kilometers away, in west Houston, fans of Young Adult Supernatural Romance novels recently packed the Blue Willow bookstore to meet four authors on a tour sponsored by their publisher, Harper Collins.

Cynthia Hand, author of two books about Clara, a teenage girl with special powers, says she has found a bond with her fans.

"I love the idea that we are sharing the same story, that we know the same people," she said.

Courtney Allison Moulton's books are full of sword fights and other action that she says resonates with a lot of male readers.

"I had a buddy who spent a couple of years in Afghanistan and he brought my book over there with him and he shared with the other - you know, these really tough Army guys reading my book and they are excited about the action," she said.

Supernatural attraction

The supernatural quality of that action attracts 25-year-old Exal Iraheta. 

"It takes you out of the normality that is your life, your routine life, and who doesn't want to feel special ?" she asks.

Some stories, like the ones from the popular "Twilight" series of books and movies, feature vampires as principal characters. But fans like 13-year-old Jennifer Vu say they look for other elements as well.

"I like mystery and I like suspense and I like a little bit of murder in it," she said.

The growth of this genre is good news for book sellers, like Blue Willow Bookstore owner Valerie Koehler, who expects this month’s release of the “Hunger Games” film to drive book sales the same way the “Twilight” films did a few years ago.

"When Twilight came out we thought everybody had read Twilight and we thought 'who in heck are we going to sell it to?' Well, it turned out there were a lot of people who had not read Twilight yet," she said.

But for many hard-core fans, young and old, watching the movies just can’t match what they get from reading the books.