As per this post at the official Adsense blog Google has now significantly reduced the amount of space in an ad that is clickable. Now only the title and URL of an Adsense ad will be clickable. The reason they say is to reduce accidental clicks.
I do not like this change. The thing is, Google created this type of advertising, they have been the standard, and surfers are probably used to their ads to the point where now they know they don’t need to click on the title or URL, just on the ad itself. This would only then confuse surfers.
Oh I agree that maybe reducing accidental clicks will increase advertisers value and raise rates, but that is a very long process to deal with and it doesn’t tackle the real problem sucking down advertiser value, MFA sites. In the meantime we’ll all have to tighten our belts I think.
A reasonable compromise would be to make all the text of an ad clickable and merely leave the whitespace (which is currently clickable) non-functional. That way users can click on the title, the text under it, or the URL, and be taking to the advertiser’s website.