Rebel Alliance

For Whedon, it all comes back to his own years growing up as a fanboy in Manhattan. "I don't understand creators who aren't fans," he says. "My experience as a fan was, things that I loved, I loved very hard -- Marvel Comics, science fiction, Dickens, Shakespeare, Sondheim. The things I was a geek about, I was a serious geek about."

When Buffy started to take off, in 1997, Whedon went to where the nerds were: the Internet. Trekkies and other hard-core sci-fi and fantasy fans were among the earliest settlers on the Net, in newsgroup discussions, early bulletin-board systems, and online games. Whedon's tales of mythological empowerment tapped a new wave of Webby misfits. "They were starting to build clubs, and I was able to get feedback," says Whedon, who maintains an active presence on fan sites devoted to him, such as Whedonesque.com. "I could do a show and go online and see what people thought of it right away," he says. "That's a crazy feeling."

"Joss would email fans of the show, have a Web site where they'd gather, have parties where he'd meet with them," says Alexander. And the more involved the fans got, the more they fed the aftermarket. "I've always believed that the only thing that's important is back end," Whedon says. "I don't care what they pay me as long as there's back-end money, because back-end money is success. Back-end money means people liked it. If someone pays you a huge amount up front, all you get is pressure." But he is quick to add a caveat: "If I don't have a purpose for repurposing -- if there's not a reason to tell a story that way -- then I avoid it."

Whedon is now experimenting with properties that originate online as short video series or Web serials. Part of the incentive is the creative freedom and low production costs. At the moment, he is creating a three-part, 30-minute serial about a hapless villain, called "Dr. Horrible's Sing-Along Blog," which he plans to make available for free online. If that show gets picked up in another medium, Whedon will own a greater stake than if the show originated on network television.

The widest-ranging current example of transmedia success is Heroes. Gaps in story lines on the TV show get filled by products in ancillary markets. So in season one, the character Hiro goes back in time and falls in love with a waitress named Charlie; while viewers don't see much of that affair on TV, the creators of the show decided to release an entire novel that revolves around it.

There's more. Every week, Heroes puts up a five-to-seven-page online comic -- complete with sponsorship by Nissan -- that continues threads from that week's episode. Each comic averages about 1 million readers. DC Comics ended up buying the series and then publishing it in print form. It was a best-selling graphic novel upon its release in November 2007 and is already in its second printing. A different example: When Cisco Systems was looking to market a new line of surveillance cameras, they teamed up with Heroes to create a Web site for the fictional company Primatech Paper; users could explore the firm's headquarters using a Cisco-branded interface that mimicked the new camera technology. Sprint sponsored a "Create Your Hero" contest designed for cell phones; players could choose the attributes of their new character, then submit it for possible inclusion in a future episode on the Web. There are weekly online and mobile trivia games (also sponsored by Sprint ), blogs written by the characters, wikis about concepts explained in books referenced on the show. The list goes on (see "The Wide, Wide World of Heroes").

Though the specific financials of the sponsorship deals and online traffic are not being made public, DVDs of the first season of Heroes sold more than 1.7 million copies (for roughly $70 million) and became NBC's best-selling DVD of 2007 -- and the second-best TV-show DVD overall, behind Planet Earth. James L. McQuivey, principal analyst of television and media technologies for Forrester Research, puts the value of Heroes' online-advertising revenue at $50 million. But the biggest sign of bottom-line success, Alexander says, is simple: "NBC wants us to do more." In fact, Heroes now is in the unique position of having two full-time producers devoted to transmedia efforts. It's a massive undertaking, relying on contributions from more than 30 writers. Heroes' executive producers maintain quality control, poring over every new detail in search of inconsistencies, which serious fans would spot in an instant. "It's critical, because if you play in this space, you're opening yourself up to the risk of catastrophe from one small mistake," Alexander says.