The influence of blogs: greater than the sum of its parts?

We've been having numerous discussions with clients recently about how to measure the influence of blogs on buying decisions.

For corporate communicators, measuring influence is an essential activity. Assigning a quantifiable degree of influence to individual publications and journalists has allowed them to concentrate their limited resources on those that are the most influential, and to discount those that are not.

It also allows them to quantify to some extent the value delivered by PR. 'We had a mention in the Wall Street Journal, which is read by 2 million business decision-makers,' they can say. That 2 million is a nice, high number, likely to convince the powers that be that PR is getting the company message across to the right people.

Of course the more pertinent, but infinitely more difficult, questions are: 'how many people read that particular article?' and 'of those people, how many were moved to buy our product?'. These aren't easy questions, and finding the answers costs the kind of money that few PR teams are able to spend.

If the exact influence of the established media is difficult to measure, the influence of blogs is even trickier. It's rare for a blogger to reveal how many readers they have, and when they do, they rarely seem impressive. This week, techblogger Robert Scoble (the 36th most popular blogger in the world, according to Technorati) revealed that he gets 6,000-22,000 visitors a day. Compared with the Wall Street Journal - hell, compared with the Aberdeen Press & Journal - those figures are tiny.

And then there's Jeff Jarvis, who infamously created a PR nightmare for Dell in 2005 when he wrote a post (actually a series of posts) about Dell's customer service practices. It caused so many other people to weigh in with their own comments, links and blog posts that it was picked up by the mainstream media. But it wouldn't be accurate to conclude from this that Jeff's blog is always influential. I know this because he once linked to a post on this blog (which I was very excited about, because I thought it would lead to unimaginable popularity and possibly also free gifts), but only a handful of people clicked on it.

What made Jeff's 'Dell Hell' story influential wasn't necessarily that it was written by Jeff Jarvis, but that it struck a chord with a lot of people. And the beauty - and danger - of the blogosphere is that a story that strikes a chord with a lot of people rapidly gets taken up by a lot of people, creating an amplification effect that can quickly become larger than the sum of its parts. It only needs one other person to write about it on their own blog - or 'share' it on Facebook, or Digg, or del.icio.us - to start a snowball effect that may see it filter all the way into the public consciousness.

So perhaps we shouldn't be asking 'how influential is this blog?', but 'how influential is this story?'. If it's interesting enough, it will be picked up and amplified. If it isn't, even if it's written about by a 'top' blogger, it's unlikely to make a difference in the grand scheme of things. PR folk, then, might be better off thinking about how to write their own stories on the internet that other people will want to read, comment on, circulate, 'share' and write about.

But that's a topic for another time.