Technorati’s Dave Sifry takes a brief look at the state of the corporate blogosphere, which he defines as ‘people who blog in an official or semi-official capacity at a company, or are so affiliated with the company where they work that even though they are not officially spokespeople for the company, they are clearly affiliated’.

That’s a pretty broad definition of ‘corporate’ but one I’ll accept for now if only because to narrow down the definition might result in a single figure blog count. As it is, Technorati only identifies around 5000 blogs, which is only 0.1 of a percent of the blogs that the site tracks.

Although Sifry explains his criteria for judging what is or isn’t a corporate blog, he doesn’t say how he identified which blogs are corporate and which are not. It must be tricky for a spider to differentiate between a corporate blog and any other sort of blog, so I’d be interested to know how he performed the count.

Unsurprisingly, the main companies using blogs externally are tech companies like Microsoft, Sun Microsystems and Macromedia. Sifry also groups together ‘media sites’ and ‘blogging companies’ which, between them, account for a sizeable slice of the pie.

Again, I’d love to see more detail on this. How many of these blogs are official? How many unofficial? How do the media sites and blogging companies slices break down? How many official blogs are marketing a specific product or service? How many are simply about improving presence?

As it is, Sifry’s report barely scratches the surface in terms of providing meaningful information about the use of blogs in business. The obvious point to make is that it only discusses external blogs. All the dark blogs – the internal blogs that are hidden away on intranets – remain uncounted and unmeasured, yet these blogs are the ones that are the most important for most blog-using companies. They are the ones that are currently providing the value.

Despite this, Sifry’s conclusion is right – blogs are slowly being accepted as being a useful business tool, and we are very much at the beginning of this process. We do, however, need to find better information than this in order to be able to convert new clients to the Way of the Blog.