If the internet killed the phone call, the smartphone has revived it.

While more and more business is conducted without human interaction, there are still times customers need to reach a business by phone and mobile click-to-call is on the rise.

According to data from BIA/Kelsey, calls to US businesses from smartphones will hit 162 billion in the next three years, a jump of nearly 75% since 2015.

For businesses that derive revenue in some way from those phone calls, attribution can be a challenge.

Those using adding a phone number to their Google AdWords ads or running call-only campaigns have up until now been able to track conversions in a rudimentary fashion only.

Specifically, Google’s conversion tracking has enabled advertisers to track when AdWords ads result in calls of a minimum length.

But recognizing that this offers a limited view of conversions, Google has announced imported call conversions, a new feature that allows advertisers to import call data so that they can attribute detailed conversion data, such as revenue generated, back to the calls generated by their AdWords campaigns.

As Amit Agarwal, Google’s senior product manager for Mobile Search Ads, explained:

“You can also distinguish between various types of customer actions that you may value differently. For example, the travel advertiser might assign revenue amounts to different call types like new bookings, rate requests, service calls, and customer upsells to a larger trip package.”

The data from imported call conversions can be used with Google’s target return on ad spend (ROAS), an automated bidding strategy that is designed to help advertisers realize an average return on ad spend that they specify across all of their campaigns, ad groups and keywords.

To import call conversions, advertisers must minimally supply a phone number, call start time and call length. Custom conversion events can be defined, and for each, advertisers can specify an optional conversion time, conversion value and conversion currency.

Already, Google says advertisers using imported call conversions are using the data to realize significant gains in their campaigns.

Insurance provider Nationwide, for instance, says that “since including imported call conversions into campaign optimization, we’ve been able to increase spend on top-performing, call-driving terms by nearly 3x. This has even helped us identify new keyword expansion opportunities from search queries we wouldn’t have otherwise found without increasing our investment backed by imported calls data.”