The media agency's latest Advertising Expenditure Forecasts show that next year mobile will account for 12.4% of global adspend while newspapers will take 11.9%. In terms of actual value, mobile advertising will grow 38% in 2016 to US$71bn, while newspaper advertising will shrink 4% to US$68bn.
Mobile advertising is the driving force behind the growth of the entire advertising market, ZenithOptimedia stated, as it will contribute 83% of all new ad dollars between 2014 and 2017.
"Mobile technology is rapidly transforming the way consumers across the world live their lives, and is disrupting business models across all industries," said Steve King, ZenithOptimedia's CEO, Worldwide.
"We are now witnessing the fastest transition of ad budgets in history as marketers and agencies scramble to catch up with consumers' embrace of the mobile way of life."
And as mobile continues its inexorable rise, so print continues to decline across most of the world. ZenithOptimedia predicts that newspaper adspend will shrink by an average of 4.9% a year through to 2017, while magazine advertising will shrink by 3.2% a year.
Their combined share of global adspend will fall from 19.6% this year to 16.7% by 2017.
In that year, internet advertising is expected to account for 34% of global adspend, slightly behind television's 35.9% and is likely to gain the top spot in 2018 on current trends.
Total adspend is forecast to grow 4% this year to reach US$554bn before accelerating to 5% in 2016, thanks to the four-yearly boost supplied by the summer Olympics and US presidential election.
ZenithOptimedia also noted that "mature markets" – North America, Western Europe and Japan – would contribute more to global adspend growth this year than "rising markets" for the first time since 2006, although it added that this was "a temporary aberration".
Warc's own International Ad Forecast, released last month, expects advertising expenditure among newspapers to decline an average 8.3% this year and next, while total online spend should rise 14.2%.
Total adspend is forecast to rise 2.8% worldwide this year, and a further 4.5% next year, Warc's research shows.
Data sourced from ZenithOptimedia; additional content by Warc staff