KEI - Keyword effectiveness Index, here's the formula for the same -
[url removed, login to view]
KEI = P^2/C
P - no of searches of the Keyword per month
C - Competition
The PHP script should be able to take upto 10 Keywords at a time as Input & display a table with the following -
Keyword - Searches - Competition - KEI - Avg PR
Avg PR - Is the average pagerank of top 10 Google results for that Keyword.
While bidding :
1. Mention which source of data you can use for "Searches" ?
2. "Competition" data can be obtained from Google search.
3. If you need to use data from anohter source which needs CAPTCHA input, then it could be done with a [url removed, login to view] API plugin.