Sponsored content: this article was rewritten by the editor of SEW, in conjunction with Marchex, to include new research in August 2016.

Whether someone is searching on their mobile device for a restaurant, a local service, or a car rental, the presence of a click-to-call button increases click-through rates and brand perception.

You’ve probably seen a click-to-call button before. It’s the little telephone symbol that appears when you carry out a local search…

It’s this simple two-tap process that makes dealing with businesses and retailers so much easier when you’re out and about. There’s no fiddly form-filling or complicated navigation. You just tap to make a direct call.

It’s this ease-of-use that makes click-to-call one of the most important features for all businesses with a mobile presence. And many studies back this up.

The power of click-to-call

An older survey of 3,000 mobile searchers by Google in 2013, revealed that 70% of mobile searchers click-to-call a business directly from Google’s search results.

However in 2015, the mobile advertising analytics company Marchex suggested that the number of click-to-calls (or call extensions) from mobile would increase from 40 million phone calls monthly in 2013, to nearly one billion in 2015.

According to Marchex’s report, it was predicted that in 2015 Americans would spend more than $1 trillion in click-to-call ecommerce.

And recently, BIA/Kelsey estimated that there will be 93 billion consumer-to-business phone calls made from smartphones, and this is expected to grow to $162 billion by 2019.

As for call commerce opportunities per vertical, automotive is the leading category with $15.9 billion ad spend.

This is followed by cable and telecom ($15.5 billion), financial services ($15.5 billion), home services ($5.4 billion) and travel ($2.3 billion).

AdWords click-to-call

Within AdWords, Google generated more than 40 million calls each month – 75% of those calls lasting longer than 30 seconds, and the majority of calls from ads lasted an average of six minutes. This suggests that most mobile searchers aren’t looking for quick information.

On average, Google said that AdWords advertisers who implement click to call see an 8% increase in click-through rate.

And what about businesses that don’t offer a call option? Almost half of those surveyed said “the lack of a call option would lead them to be both frustrated with the business and more likely to turn to another brand.”

Additionally, 33% said that they would be less likely to refer the brand to others and would be less likely to use the brand in the future.”

Where marketers need to be careful

However there is a potential blindspot when it comes to click-to-call. Advertisers invest heavily to drive phone calls from consumers but there’s little visibility into which keywords result in desired sales. Advertisers are ignoring attribution.

Marchex analysed more than 1 million phone calls made directly from mobile search ads and it estimated that marketers spent more than $4 billion on mobile search ads in 2014 to drive phone calls.

As the study reveals, “This means that lack of keyword attribution in click-to-call is one of the biggest blind spots that exist in mobile advertising today.”

If you want to invest wisely in click-to-call, you need to monitor keyword attribution, measure customer intent and include keyword level data in your paid search automation platforms.

Sponsored content: this article was rewritten in August 2016 in conjunction with Marchex.

Marchex is the mobile advertising analytics company that connects online behavior to real-world, offline actions. You can find out more about the Marchex Call Analytics For Search solution here.