This work is licensed by Portent Interactive under a Creative Commons Attribution-Share Alike 3.0 United States License.
Click here to download the keyword measurement spreadsheet.
You can read the article explaining it here, on Conversation Marketing.
This spreadsheet, and the formula in it, are licensed under the Creative Commons:
This work is licensed by Portent Interactive under a
Creative Commons Attribution-Share Alike 3.0 United States License.