MOUNTAIN VIEW, CA: Google is looking to "maximize click quality" on mobile ads by blocking certain types of inadvertent clicking that lead to frustration for consumers and to increased costs for advertisers.

"Even as smartphone and tablet screen sizes get bigger, it can be hard for our fingers to keep up," said Pasha Nahass, Google mobile display ads product manager, in a blog post. "It's still so easy to click when you mean to swipe or to tap on a link or ad you didn't mean to."

A survey of 1,000 smartphone users by consulting firm PwC last autumn showed that almost half (49%) had clicked on a mobile ad by accident.

The same study revealed that 9% had clicked on an ad intentionally but had not viewed it all, while just 6% had clicked on an ad intentionally and subsequently interacted with the brand; 37% said they had never clicked on a mobile ad.

"As we continue to enhance our display ad formats to make them more engaging, we also strive to maximize click quality," Nahass added.

The latest improvements mean that smartphone users will have to click on the central part of the image to get to an advertiser's site or app. Google said it had identified the border area as being particularly prone to accidental clicks during scrolling.

There will also be a slight delay before ads become clickable, a period long enough, Google said, to give users time to assess the ad's content and to eliminate accidental clicks by people who hadn't expected to see an ad.

A third refinement will means that when users see in-app interstitial ads they will not be able to click the app icon of an install ad because of its proximity to the 'ad close' button. Instead, users will have to click on the call-to-action button to go to the app store page and install the app.

Not only should these steps reduce costs to advertisers as they will have to pay for fewer unintended clicks, but conversion rates should also increase. Google reported a 15% average conversion rate lift on ads that have included these updates.

Data sourced from Google, AdWeek; additional content by Warc staff