They call it the Cartoon Network Effect, and it can send the sales of graphic novels—particularly manga titles—soaring.

Consider the moderately popular manga series Bleach. The anime debuted September 9 to ratings success on Cartoon Network's Adult Swim block. Since then, sales of the Viz Media graphic novels, first published in 2004, have spiked: sales on Volume 1 rose 40% in bookstores into Nielsen BookScan's Top 10 on the graphic novel chart, while in comics shops, it jumped to the #7 sales spot.

The effect is most pronounced with manga and anime, where publishing and animation generally have a more direct connection with one another than do American comics properties. And as more comics are adapted for television, more opportunities arise for publishers. For instance, more cable channels are hopping on the anime bandwagon. The Independent Film Channel is adding an hour of anime this winter featuring Basilisk(Del Rey) and Gunslinger Girl (ADV); both have manga already available in the U.S. Basilisk is the first book in Del Rey's manga lineup to get a TV spot, and the imprint is planning a cross promotion with IFC.

But converting large television audiences into graphic novel readers is an inexact science that varies depending on the property. "There has to be a good correlation between the target audience of the two productions, animation and books, which doesn't happen 100% of the time," says Milton Griepp, CEO of the pop culture retailing site ICV2.com. For instance, despite the ratings success of the Fantastic Fourcartoon, the large number of FF books available—none of which tie in directly with the show—leaves readers with a multitude of jumping-on points, unlike the clear entry point for, say, a Naruto.

Viz has arguably been the most successful publisher in this arena, with a long list of anime-manga hits, from Naruto and Pokémon to Zatch Bell! and OnePiece. Liza Coppola, senior v-p, marketing, at Viz, says an anime series will create a spike in sales of at least 30%—and often much higher.

The sweet spot for Viz's action properties is boys ages six—12, which meshes perfectly with the demographics of the Cartoon Network and the Kids' WB animation block. Coppola says she has no figures on how many viewers read the comics and vice versa, but she believes the crossover factor is significant. "I don't think they're separate audiences," she says.

Properties don't need to move huge numbers to be a success. Coppola says Inuyasha,a popular Viz fantasy manga,continues to sell respectably, with increases coinciding with the release of new movie installments. Marc Buhaj, v-p of programming and scheduling at the Cartoon Network, says the broadband Toonami Jetstream has boosted such niche titles as The Prince of Tennis. ADV's Manga sales manager, Chris Oarr, points to Neon Genesis Evangelion: Angelic Days, another Adult Swim manga entry, as a consistent top 20 seller on Nielsen BookScan—both volumes one and two debuted in the top three graphic novels at Barnes & Noble.

For American comics properties, the benefits to graphic novel sales from animation are more vague. Cartoons based on Marvel and DC Comics characters usually deviate significantly in story details from the comics.

DC publishes comics and digests that mimic the animated style of The Batman Strikes!, Teen Titans Go!and Justice League Unlimited. These titles are aimed at a general audience outside the comic book specialty shop system, but they don't rival the sales of top manga titles in bookstores. However, DC continues to pursue this audience: it just launched a Kryptocomics miniseries. In addition, Legion of Superheroes, based on DC's long-running SF superhero title, has been a hit this fall on the Cartoon Network and the Kids' WB, and DC is planning an ongoing periodical comics series based on the cartoon written by J. Torres, Scott Beatty and writers from the show.

Buhaj says a smart reinterpretation of these properties can work wonders in animation. That approach made Teen Titans a hit show that bore little resemblance to the comic that spawned it. "The audiences we often need for our broad animation series is a little younger, so there can sometimes be a gap there," he says, and older audiences may not be interested in books based on younger-skewing animation.

While cross-promoting to take advantage of the Cartoon Network Effect might seem like a win-win, some publishers point out it isn't always that simple; coordinating efforts can be tough when manga and anime are licensed to different companies. Still, as the Effect is more and more prevalent, more promotional opportunities will be explored. For instance, ADV has manga and anime divisions, and the video-on-demand Anime Network. "In the coming year, you'll see ADV being more aggressive with cross promotion within the company and at other companies to strengthen underlying franchises," says Oarr. Graphic novel publishers may only be beginning to benefit from TV. Consider that there is not yet any animated version of shojo manga—the wildly popular subgenre that targets teenage girls. "We'd love to have a shojo network out there," Coppola says. "I think that's the dream of a lot of publishers."