The article points at a 7% reduction in clicks across the Google ad network between December and January, but if I do recall, Google recently edited the ads to where users had to click the links directly rather than the square that housed the ad in efforts to reduce unintentional clicks.
yup, it really put a large dent in my clicks but I wasn't able to find any viable competition that paid out as well
some adsense users have gone so far as to suggest to potential advertisers to use image ads over text to increase the click through rate again
Do you know if it's against the ToS to create image ads that resemble the text ads? I can see this working great, though split testing would be a bit harder since you wouldn't be able to tell which of the 'ads 'the user clicked.