Western Europe will see a noticeable drop in growth in 2017 to 2.4 percent among uncertainty post-Brexit and the general elections in France and Germany, while Central and Eastern Europe will both grow by around 5.6 percent, a similar pace to 2016.
Asia-Pacific is forecast to see a growth rate of 5.4 percent, which is similar to this year's figure. Meanwhile, Latin America's ad spend is set to grow the most, at 6.2 percent, helped by the 2016 Olympic Games and a general economic recovery.
While the global growth rate in ad spend is set to slow next year, MAGNA states that this is still "faster than what should be expected in the current economic environment".
It suggests that this is due to an increasing spend on search marketing and social media, with Facebook and Google together controlling 54 percent of the global digital advertising market, up from 44 percent last year.
Programmatic technology, which automates online ad placement, will continue to be "a key driver of media-buying activity and innovation," says MAGNA, and is forecast to be worth $42 billion globally in 2020. The U.S. is the largest market for programmatic advertising, followed by China, Japan and the U.K.
MAGNA expects global digital ad sales to grow to $299 billion by 2021, making up 50 percent of the market. Australia is likely to be a big spender here, with 65 percent of its ad budgets going on digital by 2021, while China is likely to spend 59 percent and the U.S. 56 percent.