Why should you link your client’s AdWords account to Google’s Webmaster Tools?

See which campaign have the biggest changes in clicks, costs and conversions
See how often your ads rank higher in search results than those of other advertisers participating in the same auction
See if people reach your client’s website via ads or organic search results
See how your ads performed when triggered by actual searchers

Explanation: The new paid & organic report provides a holistic view of your text ad stats and organic listings at the query level, letting you analyze strengths and gaps in your overall search presence. This also gives you insight into how your paid text ads and organic search listings work together to connect your business with people searching on Google. Read more here

See all AdWords Fundamentals Questions and Answers here.