Google is fighting a small but annoying problem on mobile devices: fat-finger ad clicks.

In a company blog post Thursday, Google said that its data show that most of the time when people accidentally hit ad links its because they’re tapping near the bottom of their screens as they scroll through a page.

To address the problem, Google has added a step to the process: It now asks users to confirm that they meant to click on the ad before it sends them to the advertisers’ site.

It’s a small change, but one that fixes a persistent annoyance that hampers Web readers and mobile gamers.

The move is also good for advertisers, Google said: It improves mobile ad conversion rates because users are more likely to click only on the ads they actually want to see, thus lowering the number of errant clicks that advertisers have to pay for.

“Implementing confirmed clicks is an important step that we think will benefit users, advertisers, publishers and the mobile ecosystem overall, and we’ll continue to look for ways to improve mobile ads for everyone,” said Allen Huang, Google’s product manager for mobile display ads.

Mobile advertising is a difficult endeavor but a crucial revenue possibility for a lot of companies. The smaller screens on tablets and cellphones make it hard to display a tempting message without obstructing whatever users are trying to see on their devices.

Google has been changing the way it displays its own content on mobile devices, as well. For example, the layout of its encyclopedia-like Knowledge Graph — which the company says has culled 18 billion facts and connections from the Web — was designed in part to make the most pertinent facts in a search query easy to see on a small screen.

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