Microsoft sought to deepen the "Halo" mystique with interactive campaign elements designed to whet the appetite for fans and broaden the "Halo 3" audience, underscoring the epic nature of the game for consumers already accepting of long-term entertainment series, from "Harry Potter" to "Pirates of the Caribbean." Many of the interactive aspects were successful, in part because they followed the "less is more" formula of increasing interest by withholding information.

Microsoft ran what it called the "Iris" campaign through the summer. Essentially a high-tech, interactive scavenger hunt, Iris featured five "episodes" that provided viewers with clues and puzzles that, when solved, revealed previously unknown details about the "Halo" back-story and the Master Chief character's origins.

Iris resulted in some truly unique online experiences. For example, the third episode featured a cell phone ringtone that unlocked a 3D animation on http://www.halo3.com/ when played into a microphone-equipped PC. In another episode, participants received a clue by entering their street addresses in Windows Live Maps, which directed them to a local Best Buy or Circuit City where in-store kiosks contained clues that, when combined, revealed the IP address of the next Iris server. The intriguing and well-thought-out campaign succeeded in building word-of-mouth, initially propagated on gamer blogs but eventually reaching a wide enough audience that the campaign was covered by The Wall Street Journal.

"Halo 3" game developer Bungie Studios has established a name for itself when it comes to successful viral marketing campaigns. Moving beyond merely using cryptic emails to heighten the mystery around a game's universe and back-story, the campaign for "Halo 3" involved publicizing real live "protests" by the game's Society of the Ancients that occurred around the globe, most notably in New York and London.

Protest flyer

In late spring of 2007, Microsoft launched an unprecedented public beta program for a portion of the "Halo 3" multiplayer game. More than 820,000 participants logged more than 12 million hours of online gameplay and, in turn, spawned another huge round of buzz building via world-of-mouth, message board postings and so forth.

This stoking of the franchise's already fervent fan base contributed to the posting of more than 15,000 videos to YouTube related to "Halo 3" to date, in addition to websites, fan artwork and fiction and even covers of the game's soundtrack in everything from garage rock, pep band and talent show forms.