The Keyword Effectiveness Index ( KEI )
When launching an online marketing campaign or a search engine optimization the keyword effectiveness index will facilitate the measure of competitiveness. Now that you've found possibly 100's of keywords that would fit the description of your products or services, and could drive a massive targeted traffic on your website, a lookup to the competition on each of those terms is essential.
Three axioms are the basement of the KEI :
- The KEI of a keyword should decrease if the number of competitors increases.
- The KEI increases if the number of searches increases. If a search term becomes more popular and the competition is stable or growth slowly, you have a more competitive term.
- When simultaneously a keyword becomes more popular and more competitive and the ratio between popularity and competitiveness remains identical, its KEI should increase.
There are many possibilities to satisfy those three axioms. The equation used by Wordtracker is the most used over the online marketer community. The London based company WordTracker is a reference for keyword research of search engine marketing professionals and search engine optimizers. This company has access to data within very large meta crawlers, and covers up to 150 million of searches per month.
The chosen formula is KEI = (P^2/C), where KEI is the square of the popularity of the keyword and divided by its competitiveness. This formula satisfies all the 3 axioms:
- If P increases, P^2 increases and hence KEI increases. Hence, Axiom 1 is satisfied.
- If C increases, KEI decreases, Axiom 2 is satisfied.
- If P and C both increase such that P/C is the same as before, KEI increases.