The "Halo" legacy is one that in many ways represents the state of the video game industry as a whole. Top titles are more than just games; they are entertainment properties on the level of blockbuster movies, spawning sequels, spin-offs, soundtracks and collectible merchandise. The current development process for a major video game title bears more in common with the "Lord of the Rings" trilogy than "Pong." Because of the confluence of modern-day multimedia entertainment opportunities, games require equally broad marketing campaigns in order to catch the consumer eye. As a game developer, you aren't just competing with other game titles, you're competing with movies, television, YouTube and MySpace.

When it comes to sequels, video games do have one unique quality, however. They are almost always better than the original. So when the third installment of the legendary "Halo" franchise was announced, its marketing campaign pretty much hit the ground running without having to do anything. The first game in the series, "Halo: Combat Evolved" single-handedly "made" Microsoft's Xbox in 2001. It is considered by many to be the most influential first-person shooter game ever made for a console. "Halo: Combat Evolved" and "Halo 2" have since created a global cultural phenomenon, selling more than 14.8 million units (equivalent to roughly $600 million) and logging nearly 1 billion hours of multiplayer time on Xbox LIVE.

The franchise's reach has also expanded into other games, books, graphic novels and toys. Its legion of fans -- known as the "Halo Nation" -- range from everyday gamers to Oscar-winning filmmaker Peter Jackson, who is producing a new interactive game set in the "Halo" universe and may produce a feature film, as well. To put its popularity into perspective for non-gamers: when "Halo 2" was launched in 2004, its official strategy guide was second only to "My Life" by Bill Clinton on the best-seller list.

So how do you execute a compelling marketing campaign when you're already starting off with one of the biggest worldwide entertainment properties in history? We talked to Microsoft to find out how the company was stoking the flames for an already hotly-anticipated product, and discovered that some interactive elements of its marketing campaign might, much like "Halo" itself, change the way we think about the medium.

Author notes: John Conroy is a marketing consultant with Los Angeles-based Cooperson Communications. Read full bio.