I am implementing the Keyword Effectiveness Index (KEI) into the Maverick Keyword Researcher. However, the original formula does not work with Google keyword statistics unless I make some tweaks to it.

First up, let’s take a look at the official explanation of the KEI by its creator, Sumantra Roy:

The KEI is a measure of how effective a keyword is for your web site. The derivation of the formula for KEI is based on three axioms:

1. The KEI for a keyword should increase if its popularity increases. Popularity is defined as the number present in the “Count” column of WordTracker. This axiom is self-explanatory.
2. The KEI for a keyword should decrease if it becomes more competitive. Competitiveness is defined as the number of sites which AltaVista displays when you search for that keyword using exact match search (i.e. you should use quotes around the keyword). This axiom is also self-explanatory.
3. If a keyword becomes more popular and more competitive at the same time such that the ratio between its popularity and competitiveness remains the same, its KEI should increase. The rationale behind this axiom requires a more detailed explanation. The best way to do this is to take an example:

Suppose the popularity of a keyword is 4 and AltaVista displays 100 sites for that keyword. Then the ratio between popularity and competitiveness for that keyword is 4/100 = 0.04.

Suppose that both the popularity and the competitiveness of the keyword increases. Assume that the popularity increases to 40 and AltaVista now displays 1000 sites for that keyword. Then the ratio between popularity and competitiveness for that keyword is 40/1000 = 0.04.

Hence, the keyword has the same ratio between popularity and competitiveness as before. However, as is obvious, the keyword would be far more attractive in the second case. If the popularity is only 4, there’s hardly any point in spending time trying to optimize your site for it even though you have a bigger chance of ending up in the top 30 since there are only 100 sites which are competing for a top 30 position. Each hit is no doubt important, but from a cost-benefit angle, the keyword is hardly a good choice. However, when the popularity increases to 40, the keyword becomes more attractive even though its competitiveness increases. Although it is now that much more difficult to get a top 30 ranking, spending time in trying to do so is worthwhile from the cost benefit viewpoint.

A good KEI must satisfy all the 3 axioms. Let P denote the popularity of the keyword and C the competitiveness.

The formula that I have chosen is KEI = P2/C*1000, i.e. KEI is the square of the popularity of the keyword multiplied by 1000 and divided by its competitiveness. This formula satisfies all the 3 axioms:

1. If P increases, P2 increases and hence KEI increases. Hence, Axiom 1 is satisfied.
2. If C increases, KEI decreases and hence, Axiom 2 is satisfied.
3. If P and C both increase such that P/C is the same as before, KEI increases since KEI can be written as

KEI = P2/C*1000 = P/C * P * 1000. Since P/C remains the same, and P increases, KEI must increase. Hence, Axiom 3 is satisfied.

You may be wondering why I am multiplying the figure by 1000. The reason is that since the popularity will be very small compared to the competitiveness, the KEI for most of the keywords will be in decimals. This makes it slightly difficult to use. However, introducing the 1000 makes it easy to compare the KEI between different keywords.

Note that the formula for KEI is not unique. In fact, this is one of the nice things about the KEI. If, instead of using 2, you use any power of P greater than 1, the resultant formula will also satisfy the 3 axioms. For example, P1.5/C*1000 and P3/C*1000 both satisfy the 3 axioms. The exact power of P that you choose depends on how much emphasis you want to give to the popularity of a keyword viz-a-viz its competitiveness. Higher the power of P in the formula, higher will be the emphasis on popularity. If you are very confident about your search engine positioning skills, choose a higher value for the power of P.

If you are not that confident about your search engine positioning skills, choose a lower value for the power of P (but the power should still be more than 1). Thus, the KEI can be adapted to your skill level! Feeling confused as to which power you should choose? Stick to 2. It maintains a nice balance between both popularity and competitiveness.

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You can use the concept of KEI or any derivation of it in your own articles as long as you display the following resource box at the end of the article:

The Keyword Effectiveness Index was invented by Sumantra Roy. Sumantra is one of the most respected and recognized search engine positioning specialists on the Internet. For more articles on search engine placement, subscribe to his 1st Search Ranking Newsletter by sending a blank email to 1stSearchRanking-subscribe@listbot.com or by going to http://www.1stSearchRanking.com.

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Keyword Effectiveness Index (KEI) with Google Keyword Data

I hope that wasn’t too much math for you to understand. The KEI was created quite a few years ago while Altavista was still some kind of big shot in the search engine industry. Today, Google is the king of the search engines so we need to use Google’s data instead of Altavista and Wordtracker.

I tried using the original KEI formula with Google keyword date and the numbers looked unbelievably good. So good that is must be false.

Let’s replace all the Competion and Popularity jargons with something easier to read and remember. So here’s the KEI adapted to Google’s keyword data:

KEI = Google Search Count² / Google Search Results x 1000

Let’s use the keyword phrase “internet marketing” as an example. I shall use the exact match to search for internet marketing at Google.com. Please note that exact matching on Google.com refers to the use of quotes around the keywords wheareas brackets [] are used for exact matching on Google AdWords. Please refer to the Google Web Search’s search basics and Google AdWords’ keyword matching options for more information on the differences between Google’s matching options on Google.com and Google AdWords.

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My search settings are as follows:

• Country: USA
• Language: English
• Google.com exact matching
• Google AdWords exact matching

I get my keyword data from the Google AdWords Keyword Tool and Google.com. I shall use the Global Monthly Search Volume divided by 30 for my Google Search Count and the number of results I see in the top right hand corner of Google.com’s search pages for my Google Search Results. The original formula uses daily search counts from Wordtracker so it is best that I use a daily search count from Google to get the formula right.

So here’s what I’ve got…

KEI = (201000/30)² / 44400000 x 1000
KEI = 1011.04

1000 is a really good KEI index. In fact, it is too good to be true. It should not be that easy to rank for the term “internet marketing”. The problem with this formula is the x1000 part at the end. If you remove that, the formula seems to make more sense. Google is a monster compared to Altavista and I believe there is no reason to multiply the results by 1000.

What if we don’t multiply it by 1000? Here’s what the KEI index will be:

KEI = (201000/30)² / 44400000
KEI = 1.01

I prefer the tweaked formula because the number returned makes more sense to me.

Updated Keyword Effectiveness Index (KEI) Formula for Google

If you on using the KEI for your web site’s SEO research, here’s my update KEI formula for your quick reference.

KEI = (Google Search Count/30)² / Google Search Results

There could be a better way of calculating the KEI. some people use the “allintitle” search parameter to get different results. If you know a better tweak for Google keyword data, please let me know.