[cbsmith]

First: it may not be quite so apparent from the screen shot, but the ad is framed to make it distinct form the rest of the app. Going further might well do more harm than good, as it could disrupt sight lines and make the UI garish regardless of ad content. The ad itself also draws distinction with the surrounding widgets by employing a different font, a different icon style, a different background, and a different icon size.

As the article describes, people aren't misclicking because they've looked closely at the ad and mistaken it for an application function. Misclicks are predominantly people who really aren't sure what they are clicking on, don't know they are clicking, and/or didn't intend to click at all.

Either way, in practice Yahoo's optimization efforts if anything create incentive to minimize misclicks, not the other way around.