The key to achieving high placement on organic Search Engine Results Pages (SERPs) is the Keyword Effectiveness Index (KEI). Calculating KEI values provides a rating system to evaluate the effectiveness of long tail keyword phrases. Search terms with a greater KEI value rating increase the probability of a high placement in the SERPs.
Sumantra Roy, President, 1stSearchRanking invented the equation used to calculate KEI. He has granted permission to reprint his original article below. Please note: Revisions have been made to reflect changes in the market place.
In the original article examples were given using AltaVista. AltaVista is now owned by Yahoo! In the 2nd quarter of 2008 AltaVista’s global market share was .09%. All of the examples below have been updated for Google. In the 2nd quarter of 2008 Google’s global market share was 78.35%.
The short version of the equation to calculate a KEI value is the number of times a long-tail keyword phrase was searched in the last 90 days, squared, divided by the number of competing mentions. A competing mention is a web pages on which the phrase is present, regardless of whether it’s present in the meta tags, attributes, tags, links, or the page’s content (text visible on a page). Obviously, given that the number of competing mentions a search engine could have indexed will differ, the KEI values for the same long-tail keyword phrase will correspondingly differ in each search engine.
The Long-Tail keyword phrase in the example below (using search figures from the United States), “fig preserves recipes”, was searched 1,432 times in the 90 days preceding July 27th, 2008. Google has indexed 80 competing mentions. This gives a KEI value in Google of 25,632.80. MSN Live Search has indexed 109 competing mentions. This gives a KEI value in MSN of 18,813.06. Yahoo! has indexed 160 competing mentions. This gives a KEI value in Yahoo! of 12,816.40.
|Long-Tail Keyword Phrase||Date||Searches||Google KEI||MSN||MSN KEI||Yahoo||Yahoo KEI|
What does all of this mean?
Long-Tail keyword phrases with KEI values above 400.00 are golden. Any phrase with a KEI value 4.00 is OK—though, generally, I recommend that sufficient KEI research be completed to achieve a depth of 100 long-tail keyword phrases with a KEI value above 20.00. Please be aware that long-tail keyword phrases with more than 1,000 competing mentions are often too competitive to render the same benefit as a search term with a similar KEI value that has substantially fewer competing mentions.
The larger task is one of implementation.
Having completed sufficient KEI research to be armed with 100 long-tail keyword phrases the question with existing sites is how many pages will be revisited? At a minimum I recommend the home page and all pages that link from it. If all 11 tags and attributes to which Google pays attention need to be revisited this could easily average an hour if not two hours per page. At what point does that become cost prohibitive?
Implementing proper (Best Practice) Search Engine Optimization (SEO) on a new page or as a site is built requires only 20-30 minutes per page. Obviously, it’s considerably more cost effective to perform implementation during an initial build rather than having to retrofit tags and attributes with new KEI research—esp. if the tags and attributes weren’t included with the initial page build.