Recently I had a heated argument with one of our clients about using the word “click” in Google AdWords display banner ads. There are many questions about inappropriate language on Google AdWords, especially for banner or flash ads. Most advertisers take unnecessary precautions because they are worried that the design will be disapproved by the Google Policy Team. Google prohibits advertisers from using the word “click” or “click here” as a call to action in text ads, which is clearly stated on the Google Policy Page under “Inappropriate language ”:
The words “click” or “click here” could be easily replaced in these text ads by the words follow, see, check, find etc.
However, as a Paid Search Strategist at WordStream, I receive a lot of questions when it comes to a banner or flash ad design. Many AdWords users are confused on this point or don’t know that they can take an advantage and use the word “click” in their banner ads.
No “Click to Trick” Ads in AdWords
The Google policy is little confusing when it comes to inappropriate language for image ads . The Google Image Policy page  puts a lot of emphasis on the idea that the banner can’t fade into a website, look like a site or system warning message, or otherwise confuse visitors with the design in order to increase amount of clicks. But it doesn’t prohibit advertisers from using a button that says “click here.”
To get a final answer, I contacted the Google team and received the following reply: “Per our image ads  policy, we allow the term 'Click here' in image ads” (click the image to enlarge the email):
In sum, using "Click here" as a call to action in a display ad is allowed by Google, as long as you don't employ any of the above "tricks."
The phrase “click here” is the easiest call to action you can create and I definitely recommend that online advertisers test it  in their banner and display ads.