How do you measure the influence of blogs?
A question that’s come up time and time again since I got involved in social media PR is how to measure the influence of a blog. Mainstream media has well established metrics for measuring influence but things aren’t quite so straight forward for blogs, so if you’re putting together a target list for a PR campaign and you need to know which bloggers you should prioritise, how do you figure out which ones have the most clout?
I recommend using a combination of the following factors to get a feel for how influential a blog is – there’s no magic bullet for this problem just yet, but with a bit of research you can build a fairly clear picture of which bloggers are worth focusing your efforts on.
Technorati
In this situation, most PR people will head straight over to Technorati to get ‘Authority’ rankings for the blogs they’re interested in working with. If you don’t already know, Technorati is the leading blog directory on the web and ranks blogs’ importance by giving them a rating which it calls ‘Authority’.
This is based on a fairly simple calculation of how many other blogs have linked to a particular blog over the past six months. Authority can (and often is) as little as zero, while the most popular blog listed on Technorati has an Authority of almost 29,000.
Although Technorati Authority is a useful guide for comparing the relative popularity of different blogs, it does have a few limitations and you shouldn’t rely on it as the sole metric for measuring blogs influence.
Google assigns every website in its index with a rating of between zero and ten, which it calls PageRank (often referred to as PR, just to confuse things) and has a major effect on how highly that site is listed in Google search results. A site with a PageRank of 10 is extremely important and will get a lot of traffic, while a site with zero PageRank will have practically no visitors at all.
Google uses a highly sophisticated algorithm to calculate PageRank, and it’s always being tweaked in order to achieve the best results and prevent spammers from abusing the system to try and drive more traffic to their splogs (spam-blogs). For this reason, I think PageRank is a very useful and trustworthy metric to use for measuring a blog’s influence level.
Google does not list PageRank in its search results – if you want to view a site’s PageRank the best thing to do is install the Google Toolbar on your browser. Alternatively, there are plenty of free PageRank checker sites you could use.
Alexa
Under normal circumstances the only person who has access to a website’s traffic statistics is the webmaster, because he’s the only person who can accurately measure that data by running stats tracking software on his web-server. But Alexa attempts to provide similar data by monitoring the web-viewing habits of ‘millions’ of web users who have the Alexa toolbar installed in their browsers.
It provides a few different metrics, but the most useful is what it calls Reach – this is simply the percentage of web users who visit a particular site over a given period. For example, Google’s Reach over the past three months is 28.9% - which means that 28.9% of internet users visited Google during that period.
A lot of people trust Alexa figures when they’re researching blogs and other websites, but I think these figures are pretty flaky, mostly because I don’t think I’ve ever seen anybody using the Alexa toolbar in real life and I can’t imagine why many people would want to use it. If millions of people are using it, I’m not sure they accurately represent the browsing habits of all internet users.
Common Sense
I think the best way to assess a blog’s influence is to take a good look at it. Browse through the archives and look at things like:
- How regularly is it updated? Some great blogs are infrequently updated, but generally speaking the more regularly a blog updates, the more likely it is to be influential.
- How old is the blog? Blogs which have been around longer have more opportunity to build up a larger audience.
- How active is the community? Do lots of people comment on the posts?
- Does the blog have many regular commenters? Popular blogs tend to draw in a community of regular commenters, so this is a good sign.
All of these things should help you to form a better idea of a blog’s influence. No single metric can really give you the full story, but when used in conjunction with each other all of these factors will give you a much clearer picture of which bloggers you should focus your efforts on.
