Viewers will spend an average of 47.4 minutes a day watching videos online this year, up from 39.6 minutes in 2016, according to Zenith's Online Video Forecasts 2017.  

This increase is driven by a 35% bump in viewing on mobile devices - smartphones and tablets - to 28.8 minutes a day. 

By contrast, viewing on fixed devices --desktop PCs, laptops and smart TVs-- will increase just 2% to 18.6 minutes a day before shrinking 1% in 2018 and 2% in 2019. By 2019, Zenith predicts 72% of all online viewing will occur on mobile devices. 

The rapid growth of video consumption is leading to equally rapid growth in video advertising. The U.S. has by far the largest online video advertising market, accounting for 44% of all global expenditure this year: $11.9 billion out of $27.2 billion. 

This is well ahead of the U.S.’s share of the overall global ad market (35%), showing how advanced the U.S. in this area, says Jonathan Barnard, head of forecasting and director of global intelligence, Zenith.

Zenith forecasts global expenditure for online video advertising will grow 23% in 2017 to $27.2 billion, up from $22.2 billion in 2016. 

Although most video viewing is now mobile, most advertising expenditure goes to fixed devices. Fixed video ad spend is estimated to reach $15.2 billion this year, compared to $12 billion for mobile video ad spend. This will flip by next year when mobile video ad spend – at $18 billion – will overtake fixed video ad spend – at $15 billion. 

According to the report, "Videos viewed on fixed devices are displayed on larger screens, and often in less distracting environments, than those viewed on mobile devices, They are more effective at conveying brand messages, and so command a price premium from advertisers."

"Video platforms that can capture the attention of the most consumers with the best content will reap the highest rewards," says Barnard. "The numbers of regular television viewers and online video viewers in the U.S. are rapidly converging," he adds. Five years ago, in 2012, 283 million people watched television in a given month, while 172 million watched online video. This year during the same period, 293 million will watch television and 221 million will watch online video. In 2019 Zenith predicts 296 million will watch television and 236 million will watch online video in a given month.

This year’s edition covers 63 key markets, up from 57 last year. Zenith defines video content as everything viewed over an internet connection, including broadcaster-owned platforms like Hulu, ‘over-the-top’ subscription services like Netflix, video-sharing sites like YouTube, and videos viewed on social media, like Facebook.