It's no secret in publishing that vampire books remain hot, and the House of Night series by P.C. Cast and her daughter, Kristin, is piling up big numbers and attracting a growing international audience. First launched in 2007 with Marked, the series, about a “finishing school for vampires,” has sold more than seven million copies in North America in a combination of trade paperback and hardcover, according to Matthew Shear, senior v-p and publisher of SMP Paperbacks and Reference.

Originally all released as trade paperbacks, SMP moved the series into hardcover with the March 2009 publication of Hunted, which has sold 950,000 copies and will be released in trade paperback next month. The success of Hunted convinced SMP that there was a broader audience for the series, and SMP's experience since last fall has proven that conviction correct. The house republished the first four books—Marked, Betrayed, Chosen, and Untamed—in hardcover in September, and the four have combined to ship more than 500,000 copies. Shortly after the publication of those four hardcovers, SMP released the sixth book in the series, Tempted, with a printing of just over one million; Shear said the publisher has now shipped 1.1 million copies.

As part of the marketing effort for the hardcover editions, SMP included posters of the characters in each book that when combined make up one big poster. SMP also upped its marketing budget, taking out ads in People and on Facebook and using more Google Adwords looking to attract fans of Stephenie Meyer's Twilight series. “Our marketing has evolved to reach both the teen and adult markets,” Shear said, a strategy that has paid off. “At [Cast] events, there are lots of 20-somethings and older women in addition to teens,” Shear said. The series also has the obligatory Web site,, which is now generating 500,000 unique visitors monthly, Shear said. Audio copies of the book can be downloaded from the site via links to Audible and iTunes.

House of Night is selling very well outside of the U.S. Sales have been strong in Canada (where SMP did a boxed set of the first four hardcovers), and rights have been sold in 35 territories. There will be 12 books in all in the series, and the seventh, Burned, will be published in the U.S. in April.