Carter signing books at BEA this year.

Aimed at readers who like heroines that are more concerned about pulling off covert operations than pulling off the perfect outfit, the first two books in Ally Carter’s Gallagher Girls series have been steadily gaining fans for the past few years. This week, the third book, Don’t Judge a Girl by Her Cover (Disney-Hyperion), also starring teenage spy-in-training Cammie Morgan (aka the Chameleon), went on sale with a 250,000-copy first printing.

“I feel very fortunate that I get to keep writing this series and that there are people out there who are really interested to see where it goes,” said Carter, who is currently on tour (her first ever) forthe new book. “I’m a newbie so don’t exactly know what I’m doing,” she confessed, while en route to a school event in Seattle, having just arrived from launch events in San Francisco, including a writing seminar at Books Inc. and an event at Kepler’s in Menlo Park that saw more than 120 fans turn out. “Almost every girl who came through had read book one and two multiple times.”

For Carter, the success that the Gallagher Girls series has seen so far came as a surprise, and she credits bookseller support and word of mouth with helping get attention for the first book, I’d Tell You I Love You, But Then I’d Have to Kill You (2006) and pave the way for the second book, Cross My Heart and Hope to Spy (2007), which debuted on the New York Times bestseller list. “That really blew my mind,” Carter recalled. “I knew it was possible—anything is possible—but until you get that phone call you don’t really believe it’s going to happen.”

For the new book, in addition to sending Carter on the road, Disney has created a brand-new standalone Web site, which went live this week. Carter actively communicates with her readers online, via her Web site’s blog as well as a Twitter page and an online newsletter she sends out, reaching a wide fan base. “There’s no way you could possibly tour enough and do enough live events to connect with that many readers,” she said. “If you have a blog and you enjoy blogging, I think that’s a way for readers to feel that they know you.”

She cautions, though, that author blogging is most successful when it’s done “because they honestly like connecting with readers and having a creative outlet. If it’s just a sales pitch, kids will see through it.” She recalled having “languished” over a post for hours, only to see it get just 20 comments. “Then I’ll blog about why when I go to Subway I always order the same thing, and I’ll get hundreds of comments,” she said. “It’s a way to remind them we’re just people with a job. We’re no different than the people they have in their lives.”

While there isn’t any news on the I’d Tell You I Love You... movie front (Walden Media bought the option from Disney in 2007), Carter said she has finished a draft of the planned fourth Gallagher Girls book. Though a title and pub date for that bookhave not yet been set, Carter is looking forward to her next (standalone) novel, Heist Society, which Disney-Hyperion will publish in February 2010. The story stars a girl who has grown up in a family of con men and art thieves and who tries to escape the “family business” by conning her way into an elite boarding school.

“She ends up putting together a ragtag crew of other children of thieves and they track down stolen paintings across Europe,” Carter said. “It’s very fast-paced and takes place in lots of fun, exciting settings. If George Clooney and Julia Roberts from Ocean’s Eleven had a 15-year-old daughter, this could be her story.”

Don’t Judge a Girl by Her Cover by Ally Carter. Disney-Hyperion, $16.99 ISBN 978-1-4231-1638-7