As few as five years ago, the creed of ARGs was “This Is Not A Game,” the call to make the game as immersive and realistic as possible by hiding/denying the fact that it’s a game at all. For many games that had obviously fictional elements -- for instance, taking place in the future -- this could only be taken so far; nonetheless, it was adhered to as strictly as possible. Now, though, there seems to be a trend away from that. Tim Kring's Conspiracy for Good stated upfront on the main website that yes, this was a fictional story, a game. Zeroes2Heroes president Matt Toner talks about the same thing on the Transmedia Talk podcast, episode 9 with regards to their project Are You Awake. There are elements of social gaming in the property that clearly mark it as an "authored interactive event" rather than pretending to be real -- and he says that they've had positive audience reaction to that. The audience isn't baffled trying to find their way around the story, it's presented to them as such.
I think those early ARGs were getting some of their appeal from the degree to which they were immersive, the degree to which they seemed like real life. But maybe that was just a trend.
I think audiences are smart enough to understand the boundary between transmedia story and real lif, and are smart enough to act accordingly. When a blog or a twitter account is clearly in-universe, audience will respond to the characters in-character. When the hub website links to the blogs, the game, the web-series, and the production company's website, the audience won't expect that the production company is a fictional, in-universe entity.
People read books obviously knowing that they're reading a book, but the best ones are still incredibly immersive for a reader.
But there's still a boundary to be played with. Where is that line between the in-universe and out? When a character has a blog, do you have a link on that blog back to the main site, or do you keep that blog entirely in-universe? (I noticed that at least one of the blogs involved in Are You Awake has no meta-game references, no links even back to the main website that I saw.)
What if someone stumbles across the blog before knowing it's part of this fictional story? Do you trust that they pick up on it, google it, figure it out? Do you just not care?
It's definitely one of the benefits of transmedia, when it comes to things like character Facebook pages or blogs, that it blurs the lines between fiction and reality -- it lets the audience feel that these characters are real people, and there's no doubt about the benefit of that. But how far does it go?