Some people think measuring someone’s online influence is simply a matter of Googling a name, seeing what Technorati says about them, what Alexa might show and perhaps a look at how many subscribers there are to their FeedBurner RSS feed.

While those are among the activities that often can be good enough to get a quick snapshot view about someone’s online presence and what other people say about them (I wouldn’t necessarily call it influence), Edelman has come up with a new means of measurement which, at a first look, gives a far deeper and broader perspective on influence.

In a highly detailed post, Edelman’s David Brain explains the Social Media Index, a new methodology which embraces emerging platforms like Facebook and Twitter as part of the means to gauge influence:

[…] What we have tried to do is add some new ways of measuring influence via platforms like Twitter and Facebook to blog scores. This is definitely adding apples to oranges we admit. So for example, we are placing a score for Facebook depending on the number of friends someone has. For Twitter, it is the number of friends, followers and updates. And if that is not insulting enough, we are then coming to a comparative weighting of someone’s Facebook score against their Twitter and blogging score. And the most sinful step is of course the final one where we have added those scores together and come up with a total Social Media Index.

The preliminary rankings included in David’s post give a good idea of how this new indexing system works. It compares a list of 30 bloggers ranked in broadly traditional ways, and then 30 bloggers ranked according to the far broader Index where each person was given a score out of 10 based upon 6 criteria:

1. Blog – analysed Google Rank, inbound links, subscribers, alexa rank, content focus, frequency of updates, number of comments
2. Multi-format – analysed Facebook – number of friends
3. Mini-updates – analysed Twitter – number of friends, followers and updates
4. Business cards – analysed LinkedIn – number of contacts
5. Visual – analysed Flickr – number of photos uploaded from the person/s or about the person/s
6. Favourites – analysed Digg, del.icio.us

There’s an awful lot to absorb in David’s post to fully understand how the Social Media Index will work and what’s needed to give it some traction. There are probably other resources that ought to be included and no doubt will be as David and his colleague Jonny Bentwood develop the Index.

MySpace, for instance, one that David mentions. I’d also consider including emerging niche networks such as MyRagan and the Communicators Network. Plus virtual communities like Second Life.

In any event, when measuring online influence, the general idea of broadening the things you look at to also include places like Facebook and micro-blogging tools like Twitter – all tools that are rapidly growing in uptake from a business networking point of view – makes a lot of sense.