The campaign includes a phony blog, in which one of the characters in the film writes about how Sarah Marshall has broken his heart.

Rayanne Langdon, who works with us here at com.motion, wrote a post on glossblog, where she gave the campaign a thumbs up because it raises awareness and gets people talking.

That post generated a comment from Mary-Margaret Jones of Thornley Fallis’ PR Girls blog, who strongly disagreed. Mary-Margaret said the campaign was “inauthentic from the get go” because it wasn’t clear that it was a character blog. In the realm of social media marketing, she wrote, that “hurts.”

To be sure, the No. 1 rule in social media marketing is that transparency and authenticity must prevail. But once you know the rules, isn’t it okay to break them once in a while?

Take this example of a completely non-transparent social media campaign that worked. Millions have watched this YouTube video of Australian party boy Corey Delaney:

After Corey became a worldwide bad-boy celeb, the Aussie blog Random Brainwave set up a MySpace page pretending to be Corey. Media called seeking interviews; the Random Brainwave guys complied; and their website got loads of attention and (presumably) loads of new readers.

No, they weren’t transparent. No, they weren’t authentic. But as a fringe website, they could get away with it where a big brand, like say, Wal-Mart, could not. I’m usually the guy telling my clients that authenticity is critical. And 99.9 per cent of the time, it’s the absolute truth. But aren’t we still too early in the evolution of social media marketing to be talking about indisputable truths?