The Guardian reports on a Jupiter research study which suggests that, though active bloggers are few (when compared with the total numbers of internet users) they are disproportionately influential.
The strongest part of their influence is on the media: if something online suddenly becomes a story in the local press, then it matters.
PR Studies 
I tried to find more about the Jupiter Research’s report, and its methodology – but the Guardian doesn’t provide the title of the study, or when it was done. The report that might have some data on the influence of “consumer-generated content” was published back in December 2005:
http://tinyurl.com/h3zp3
Good spot, Constantin. I read three newspapers this morning (in print not online: I’m on leave and this is a leisure activity…) and found much of interest in the Financial Times, The Guardian and The Times. Yet this is the end of the four-day Easter weekend in the UK, so today’s newspapers should have been thin. Slow news periods (weekends, bank holidays, whole of August) are traditionally a good time for PR practitioners to place their stories. It looks like Jupiter Research must either have given The Guardian some early insights from some unpublished research, or they warmed up some existing research for them.
How does the media access these stories in the first place, is it just fluke, or reading some high profile blogs?