A new study from Invoca, a marketing firm specializing in call analytics, has found that 92% of phone calls to businesses were driven by digital marketing, up from 84% in 2014. The 2016 Call Intelligence Index also found that 54% of calls originated from mobile-specific channels, highlighting the importance of companies including click-to-call buttons on mobile-optimized websites and advertising.

Six of the top 10 call sources are digital marketing channels: mobile search (48%), desktop search (17%), desktop display (11%), content/review sites (9%), mobile display (3%) and email (3%). Rounding out the top 10 are radio (3%), TV (2%), newspaper (2%) and directory (2%).

“Marketers speculated that the rise of digital would kill more traditional channels like the phone call,” said Kyle Christensen, vice president of marketing for Invoca, in the study. “But what we’re seeing is the opposite. As people use their phones to interface with the world around them, they’re also calling businesses more. The marketers who will thrive in this environment will be those who optimize for calls as an integrated part of their omnichannel strategies.”

In addition, the study found that 65% of people prefer to contact a business with a phone call, versus 24% who prefer a Web form, while 63% complete a purchase offline following online search activity, and 70% have used a click-to-call button from a search ad. The study also found that women were more likely to make a phone call than men.

In March, a study from Demandbase, in conjunction with Wakefield Research, found that almost 90% of B-to-B marketers’ digital marketing mix isn’t ROI-optimized. And a recent report from ZenithOptimedia forecasted that mobile advertising will surpass desktop as the primary internet advertising medium in 2017, a year earlier than previously expected.

To compile the 2016 Call Intelligence Index, Invoca analyzed 58 million calls across 40 industries.