Interesting studies in the Spring issue of the Journal of Interactive Advertising, which issue focuses on the effects and impact of viral/buzz/word-of-mouth marketing.
Especially the paper by Alexandre Steyer, Renaud Garcia-Bardidia and Pascale Quester offers evidence for the often-heard claim that online, traditional systems of expert intelligence - which also for example function legitimate social institutions like academia, journalism, organized religion, and politics - simply do not work:
Indeed, the targeting of [opinion leaders] would appear unlikely to enhance the increased exposure by others to the brand information or, ultimately, to the product itself. Rather, a strategy aimed at the total group [...], or the introduction of (unidentified) messages to group discussions, a technique known as viral or buzz marketing, would appear just as effective.
I see this as further evidence for the unpredictability of consumer behavior supercharged by ongoing blurring of the boundaries between producers and consumers of media. There seem to be no 'automatic' or necessary (and thus: hierarchical) relationships between production and consumption cultures anymore. This is not to say there are no power laws in the new media ecology; of course, there are notorious bloggers, dominant posters, popular podcasters, celebrity modders... But their reputation is not necessarily determined by a status that is derived from some kind of institutional or professional accreditation process. Obviously, this significantly undermines the self-legitimation of media workers in multiple industries (in particular the journalists, but also consider game developers, advertising creatives, and scriptwriters for movies and television).