Granted, Sony's Year One is not exactly a property ripe for video game adaptation, and its target audience is much broader than movies whose studios put in a lot of effort at viral buzz, but if it's that the case, why bother even making one at all? It's shoddy and looks like the marketing department already knew Year One (which I liked, by the way) would already be poorly reviewed and have a weak box office showing despite the big names attached.
On the other hand, The Dark Knight, which was distributed by Warner Bros., built up a ton of online buzz from its viral websites like WhySoSerious.com, Friends of Harvey Dent, and others with help from the marketing company 42 Entertainment. The Dark Knight would have been very successful even without these sites, which took a lot of effort and money to put together. Same with the campaign for Terminator Salvation and its Skynet Research site. It's a no-brainer summer blockbuster, destined to rake in the bucks despite the many complaints from critics and fans.
District 9 is drumming up plenty of blog posts with its network of websites like Maths from Outer Space, Multi-National United, and MNU Spreads Lies. District 9 already has an audience in place because of its sci-fi bent, and because Peter Jackson, who is a mentor of sorts to director/writer's Neill Blomkamp, is one of the producers. However, it's still a big-budget blockbuster with little need from Sony to invest in such a viral campaign.
My favorite recent viral marketing campaign, though, was for Coraline, from Focus Features and the marketing company Wieden+Kennedy. You can check out their blog for details on their super-cool boxes they sent out to bloggers and "influencers," the great website, and the creepy interactive storefronts, and bus stop ads they created. What really grabbed me were the posters with keys to the Other Mother's world stapled to them that I saw around the corner from my apartment. A friend of mine who works the coat check at a club in Boston was given a bunch of Coraline keys and asked to sneak them into people's coat pockets but instead decided to hand them out. He thought the idea was a little too creepy, although he was kind enough to send me one in the mail -- of course, I'd already pulled one off one of the posters!
It's hard to measure the effectiveness of a viral campaign through hard numbers because even if you look at website metrics and media coverage there's no proof either of those translate directly into ticket sales from people who wouldn't otherwise see those movies. Some of the movies with the most effective viral campaigns naturally lend themselves to that sort of marketing because of their subjects or target audiences. But it's not hard to see that there are way more effective ways to do market your movie than a Shockwave game.