Google has announced a new conversion tracking metric for AdWords: reporting for calls placed from mobile pages. As mobile usage skyrockets, and smartphone use in particular, this should be an increasingly important metric to track for many businesses.

“Mobile advertising has created an entirely new opportunity for businesses to drive phone calls to sales teams and call centers, generating a new method for our advertisers to receive qualified incoming leads,” says Google Mobile Ads Product Manager Surojit Chatterjee. “In fact, since we introduced the click-to-call feature to advertisers over a year ago, we’ve had more than half a million customers globally run campaigns with phone extensions.”

“Two of the most common ways to get mobile customers to call you are either by listing your phone number on a click-to-call ad, or adding your phone number onto your website,” adds Chatterjee. “It’s easy to measure calls from a click-to-call ad from yourCampaign reports, but it can be more challenging to track the calls made by consumers clicking on the phone number on your website.”

Hence the new metric.

Advertiser can track clicks on their phone numbers or call buttons to the AdWords campaign, ad group, ad or keyword levels.

Google has a step-by-step guide to set up a mobile site with a phone number right here.