One by one, 10 teens trapped on an island are murdered by a serial killer in Ten, a thriller by Gretchen McNeil, due September 18 from Balzer + Bray. The author, a dedicated tweeter and blogger, has taken to the Internet to promote her novel. She is currently participating in a blog tour touting Ten, which will wrap up on the book’s pub date; she’ll take part in a live Twitter chat hosted by YA fan site Mundie Moms (using the hashtag #GretchenLive) August 31 at 3:00 p.m. PDT; and has organized an online trailer reveal “party” on September 1 at 9:00 p.m. EDT. And, in a major promotional push, McNeil is mobilizing a battalion of fans to spread the word about her novel via a grassroots, incentive-based campaign she’s named the Army of Ten.

Readers enlist in the Army online, where they embark on a mission to promote Ten as a private. After completing an assignment – to tweet that they’ve joined the Army of Ten – recruits receive a “medal” (a bookmark), and are promoted to the rank of sergeant and given another assignment and reward. Fans subsequently proceed to the ranks of lieutenant and major.

The quest culminates at the level of general, which participants reach when they follow the order to find a bookstore that is not carrying the novelafter September 18 and “ask, hound, convince, cajole, or otherwise persuade the bookstore into ordering Ten.” The names of those who successfully complete this final task will be included on the acknowledgements page of McNeil’s next book, 3:59 (Balzer + Bray, fall 2013).

McNeil conceived of the Army of Ten campaign after she learned that Barnes & Noble would not be stocking her novel. “It was a business decision on their part, and I understand that,” she says. “But not getting the book stocked by one of the last major chains can obviously affect sales, and it made it imperative for me to connect directly to readers. Instead of giving up, I decided to create a promotion with an army theme to fight my way into the marketplace. The idea exploded from there—it’s basically guerilla marketing.”

Launched on August 20, the Army of Ten currently has more than 250 recruits, some of whom have offered enthusiastic feedback on Twitter. Major Alayna calls it “a creative way to promote your book and reward the people who help.” According to Lieutenant Rachel, the Army of Ten “is a bomb way to promote! It’s super fun, and most anyone can do it! Well done. Over.” And Lieutenant Maggie says that the campaign “shows we can give back to our authors. They care enough to share great stories and we can do some legwork.”

McNeil is gratified by readers’ pre-pub reaction to Ten, which was inspired by Agatha Christie’s And Then There Were None, a favorite mystery of hers that she believes “lends itself perfectly to YA homage.” Beginning with the novel’s February cover reveal on the Me, My Shelf & I book blog, which received close to 5,000 hits in four days, the author says, “I have been overwhelmed by readers’ response every step of the way. And through the Army of Ten, people have been making a great effort to get the word out about Ten in a way I couldn’t have done on my own.”

Ten by Gretchen McNeil. HarperCollins/Balzer + Bray, $17.99 Sept. ISBN 978-0-06-211878-3