The Publicis Groupe media agency’s Advertising Expenditure Forecasts says UK adspend will be down on 2015’s 9.2%. Last year Zenith had predicted UK growth of 9.7% and hailed it as "stellar… the fastest growth rate of any mature market".
Although the slowdown began before the vote to leave the European Union in June, Zenith said the Brexit impact is likely to weaken growth "over the next few years", while global ad expenditure will remain steady at 4.4% this year and in 2017.
Zenith forecasts UK adspend to grow at between 3% and 4% in 2018 and 2019.
However, Group M’s global forecast is more sanguine about the UK, where it says Brexit "has not impacted advertising" even if it has impacted financial markets.
Last year Group M revised its UK forecast up to 7% for 2016, thanks to a surge in digital adspend growth and its latest report, published today, says its 7% forecast remains unchanged.
Both Zenith and Group M’s latest forecast, published today, say global adspend is forecast to grow 4.4% in 2018. Zenith further predicts global adspend to be 4.1% in 2019, matching a trend since 2010 when growth has hovered between 4% and 5% annually.
Meanwhile, social media adspend will become larger than newspaper adspend. Zenith predicts social media will account for 20% of all internet advertising in 2019, up from 16% in 2016, and is growing at 20% each year.
By 2019, social media adspend will be $55bn (£43.5bn), just 1% smaller than newspaper advertising, and will overtake newspaper spend the following year.
Worldwide growth in smartphone usage has led to an explosion in growth of social media platforms – particularly Facebook, which has sought to confound ad-blocking technology by blending ads seamless into its news feed.
Online video advertising is growing almost as quickly as social media at 18% a year and by 2019 is forecast by Zenith to total $35.4bn globally, fractionally ahead of radio advertising ($35bn). However, video adspend is forecast to be less than a fifth of TV adspend at 18%.