In addition to bidding for clicks, Google has announced that advertisers now have the ability to bid for phone calls, which will then be factored into Ad Rank calculations.

Bid-per-call works by assigning and placing a toll-free number – through Google Voice – next to your text ad on Google search pages. When a user sees the ad and calls the number, AdWords will forward the call to your business.

“Many businesses tell us that they value phone calls very highly and treat calls as leads,” explains Surojit Chatterjee, senior product manager for Google. “If an advertiser gets lots of calls and they bid for those calls, those calls will improve their rank and their quality score, which is very, very unique.”

All calls are logged and viewable through your AdWords reports. You’ll be able to see the number of calls received, call duration, and eventually caller area code. Additionally you will have access to detailed call information, including summaries of completed calls, phone-through rate, and call costs.

To start using this feature, you will need to set up Call Extensions and select the option to use a Google forwarding number. You will also need to enter a maximum CPP – cost-per-phone call – bid so when someone calls, Google will charge you the CPP price. Users on mobile devices can call directly by clicking on an ad, so it’s priced as a cost-per-click.

Click-to-call ads are growing in popularity and are now driving millions of calls per week. Google has already connected over 12 million calls for thousands of businesses.

Over the next few weeks bid-to-call will be made available to users in the U.S. and United Kingdom.

[Via: Adweek, Image credit: Scott Raymond]