Here’s the deal, marketers: you’re doing mobile wrong.

Mary Meeker’s most recent Internet Trends Report shows that smartphone adoption is beyond critical mass with 76 percent penetration among Internet users. Yes, mobile is huge — that’s why you invested in a responsive website, mobile search strategy, and a “mobile-first mindset.” But if you pay attention to the recent investments by the mobile infrastructure players (Google, Facebook, Twitter, even Apple and Amazon) you’ll see where the money is: phone calls.

Hard to believe? Look at the data; mobile ads are driving 54 percent of all calls to businesses according to Invoca’s analysis of 32 million calls, not to mention calls have a conversion rate of 30-50 percent, compared to just 1-2 percent for clicks. Phone calls from mobile search will top 73 billion in 2018, and it follows that we should expect 22-37 billion conversions. This presents a huge opportunity, which is why Google brings us Mobilegeddon, and why Facebook launched Hello and click to call capabilities. It’s also why WhatsApp is getting into the call business.

Smartphones are increasingly used for their original purpose: to connect two humans through live conversation. While Meeker’s report tells us mobile adoption is slowing (2014 saw 23 percent growth compared to 27 percent in 2013), the value of the channel is growing. It’s growing in part because Millennials are coming of age and buying more than Slurpees and pizzas. They’re buying big ticket items, even making B2B purchases, and a huge chunk of their path to purchase is happening on the phone. When they buy, they search and discover on mobile — and then call from mobile. Why? It’s easier to make a phone call than to fill out a mobile form or create an account to make a purchase.

Meeker’s report also notes that mobile is now the number one place for digital consumption, but marketers haven’t figured out how to convert this media consumption into revenue. Most are still thinking about mobile as a smaller form factor, not as an opportunity to connect with consumers through phone calls. That’s a huge mistake. “Mobile-first” is good, but it’s not enough. Mobile forms and responsive sites aren’t cutting it when it comes to turning interest into actual purchases. Marketers must drive revenue and relationships across every interaction — online and offline.

The imperative for us as marketers is to take all of the engagement and content on mobile and turn it into sales. Take a page from Facebook and Google and capitalize on all aspects of mobile devices. Remember that a mobile device is also a phone — a device that allows people to both click and call. “Doing mobile right” means a lot more than shoehorning a desktop experience onto a smaller screen; it means understanding how consumers want to connect with you and making it easy for them to do just that.

To learn more about the role phone calls play in the omni-channel customer journey, download the Invoca 2015 Call Intelligence Index.