(Reuters) – Money spent on online advertising has risen rapidly, a leading forecaster said, despite talk about firms trimming digital ad budgets as they question the medium’s effectiveness.

A man looks at his phone as he walks along the National Mall in Washington, U.S., March 16, 2018. REUTERS/Brendan McDermid

Zenith, owned by France’s Publicis (PUBP.PA), forecast that advertisers would spend 40.2 percent of their budgets on online campaigns this year, higher than 37.6 percent in 2017.

“For many consumers, checking their mobile devices for social media has become a regular, ingrained habit, while social media ads blend seamlessly into their mobile app newsfeeds,” Zenith said in a statement.

Mark Zuckerberg’s Facebook (FB.O) is often credited with spearheading the social media revolution that has gripped billions of users globally.

However, the world’s largest social media network faces government scrutiny in Europe and the United States following allegations by a whistleblower that British consultancy Cambridge Analytica improperly accessed users’ information.

Global advertising expenditure is forecast to expand by 4.6 percent in 2018 to $579 billion, helped by improved economic growth in China and Argentina.

The new projection marks the biggest quarterly upgrade since March 2011 by Zenith, which had forecast 4.1 percent growth in December. [nL8N1O41AI]

Workers look at mobile phones as they sit outside a construction site in Beijing, China December 6, 2016. REUTERS/Thomas Peter

Zenith added that it expected advertising expenditure to grow more slowly than the global economy as a whole…