Keyword Effectiveness Index (KEI)
The Keyword Effectiveness Index (KEI)
compares the Count result (number of times a keyword
is searched within a search engine) with the number
of competing web pages to pinpoint exactly which keywords
are most effective for your campaign.
The higher the KEI, the more popular
your keywords are, and the less competition they have.
Which means you have a better chance of getting to
the top.

Keyword or keyword phrases
less than 10 are considered poor keywords, while keywords
above 10 are good keywords. Keyword or keyword phrases
above 100 are excellent keywords and should be displayed
on your website's home page.
SearchPro
Keywords compiles a database of terms that
people search for in all of the major
search engines like Google, MSN and Yahoo. SearchPro
can tell you how often people search keywords, and
also tell you how many competing sites use those keywords.