Keyword Difficulty Tool

is used to measure the difficulty of optimizing a Web page for a key phrase for ranking with Google. The rating is given in percent. You add your key phrase and 3 top bids for the keyword in Overture. Requires a login account, Amazon API key, Google API key and a Yahoo Addlication ID.

Source: http://www.seomoz.org/tools/keyword-difficulty-tool.php

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