Google Enables Call Tracking From Mobile Landing Pages.Calls and call metrics are increasingly important to Google because they’re a form of “offline” conversion tracking that provides more visibility on the true efficacy of keywords and campaigns. Selling calls also enables Google to drive phone-based leads, which are more qualified and often of higher value than clicks.
http://searchengineland.com/google-e...ng-pages-95932
I think, it will help more in future for Adword.