What Halo did: Pissed off an entire population of fans, that's what. When Master Chief promised to "finish the fight" on Earth in Halo 2, we assumed he meant after the cut scene, or after the next loading screen… not three years, one generation of consoles and sixty dollars later in Halo 3. Still, we learned to wait.
What the industry has done since: Now we're not even surprised by the wait. With mega publishers like EA, Activision and Microsoft scheduling series to release a new entry every one or two years – seriously, you can set your watch to some of these – the cliffhanger ending is commonplace. All games are planned as franchises, and each sequel is shipped with the next sequel already in development. You know you'll get another Modern Warfare within 24 months of this Modern Warfare, for example, so you don't worry too much when Soap and Captain Price are left in a closure-lacking lurch.
What Halo did: Last decade, the videogame industry officially surpassed the movie industry in gross sales – while The Dark Knight set a day-one record for film with $67 million, Halo 3 set a day-one record for US entertainment as a whole with $170 million. And the publicity and marketing campaign matched that growth. Microsoft treated their game like a Hollywood blockbuster, with fast food licensing tie-ins, celebrity galas and Times Square photo ops. The same just happened with Halo: Reach, as any Doritos bag will tell you.
What the industry has done since: If you live in or near a city, you see the Halo effect every day. Billboards for Red Dead Redemption. Bus stops plastered in Mafia II. The tops of taxis advertising Spider-Man: Shattered Dimensions. If you live in the suburbs, we're still pretty sure you noticed that Dante's Inferno commercial during the Super Bowl. Or the Mountain Dew cans skinned with World of Warcraft elvess. The release of a game is more than a release – it's an event.
What Halo did: Um, what didn't Halo do? Novelizations such as The Fall of Reach, Ghosts of Onyx and Contact Harvest… six in total, with three more on the way, and not including the collection of short stories, the encyclopedia, the bestiarum and a handful of art books. Then there are the graphic novels and four- or five-part comic series. And the action figures designed by Todd McFarlane. And the anime produced by famous Japanese directors. And the possibility of a movie or television show, or both, from Lord of the Rings mastermind Peter Jackson. And the alternate reality games like I Love Bees. And the non-shooter games like Halo Wars. And the soundtracks. And… well, you get the idea.
What the industry has done since: Publishers and developers have realized that, if their universe is compelling enough, gamers will happily continue exploring it outside of the actual games. And pay extra money to do so. Thus, the animated prequel for Dead Space. Thus, the companion novels for Mass Effect and God of War. Thus, the comic books for Gears of War and Prince of Persia. Thus, the tie-in toys for BioShock 2 and Assassin's Creed. The list will only get longer.