12 January 2010
I’ve been looking into this a great deal since starting out in SEO, and a lot of the reports, articles and blog posts that are out there give some really good scientific answers as to what it is, but they don’t really give the beginner an easy answer.

When I started out I read lots of lots of articles but didn’t really understand them. What I hope to do in this simple and short post is give my take on KEI and how best to select your keywords.

Keyword Effective Index (KEI) - What is it?

In laymen’s terms, the KEI of a keyword or search term is the equation that you end up with that will tell you how easy a particular keyword is to rank for. What this is supposed to do is highlight quite easily which search terms to target in order to drive traffic to your site. Sounds great doesn’t it! If only it were that simple...

How to Calculate (KEI)

There are different variations out there about how to calculate KEI effectively, but I use and suggest the below:

KEI = (volume of searches per month)^2/(total number of competitors)

I said at the beginning of this article I would make this as simple as possible, so I will now attempt to explain how the above calculation works in terms of a real example (better than Derren Brown eh???)

Cheap bathroom Suites (9900)^2/17700000 = 5.54

So, the KEI of the search term Cheap Bathroom Suites is 5.54. From experience, to find an ideal search term to target that will get results quickly (and this is where I am making it simple for everybody), I would be looking for a KEI of between 20 and 150, so this search may not be the best to target initially!

Sorry to get a little complicated now, but there are reports out there which say KEI is calculated using exact matching search technology. Let’s use our example again of Cheap Bathroom Suites. If we search Google by simply typing in our search term (broad match) we get 17,700,000 competing sites, making our search term not ideal to target initially. If we use exact matching searching (placing speech marks around our search term before we search) we get 50,400 competing sites. Let’s run our equation again:

Cheap bathroom Suites (9900)^2/50400 = 1944

What a different result we get! Generally the consensus is the higher the KEI, the easier the keyword will be to target, and at 1944 we should be able to hit that in day one.

So what do we believe then? Do we listen to the articles that say that KEI is calculated using exact match search, or by broad match as in my first example? I tend to lean towards the first theory, as if nothing else, the first option will give you the worst case scenario allowing you to make a much more realistic decision.

Please bear all of the above in mind when looking into KEI, and there are thousands of calculators out there that will no doubt use a mixture of equations and searches (i.e. Broad and exact match). For this reason alone I always use my own equation, so I am happy that I am getting the results I expect to see.

As with everything in SEO do not rely totally on the KEI value when selecting Keywords use this only as a guide...Happy researching