Social at 23%, video at 19%, and search at 13% will become the fastest-growing digital formats in 2019, according to the report released Friday by Magna, a division of Interpublic Group.
Overall, digital ad sales in 2019 will grow about 12% to $124 billion in 2019, while the sale of traditional advertising will fall by 5% to $92 billion.
As digital media now accounts for more than 50% of advertising spending, with about 30% for national consumer brands, growth rates are expected to slow.
Last year marketers spent more on media than previously estimated by Magna, thanks to a strong fourth quarter.
In the data, Magna notes that U.S. ad revenue rose 9.6% to $212 billion -- up from its previous estimate of $207.5 billion.
Search advertising and out-of-home posted the biggest growth spurts in 2018, with paid search increasing 23% to $54 billion, and out-of-home rising 4.5% to $8 billion.
Digital U.S. ad sales rose more than 18% overall, in line with previous quarters, with the strongest growth coming from social at more than 28%, digital video at 32% and Search.
Amazon more than doubled its advertising revenue in 2018 -- reaching an estimated $6 billion -- and will becomes a major advertising supplier. It also increased the amount spent on advertising by 50% in 2018.
In terms of ad spend, the marketplace came in at No. 6, behind only P&G, ATT, Geico, Comcast and GM.
Out-of-home rose 4.5% to $8 billion, partly due to the huge increase of ad spend from the technology sector. OOH is the only linear media type to experience consistent organic revenue growth.
Ad sales grew by an average of more than 4% per year in the last nine years, compared to decline of 1% for all non-digital media sales such as linear TV, print, radio, and OOH.