US digital ad spend is forecast to reach $103bn (£64.6bn) by 2019, with search marketing taking the biggest slice and social media continuing to grow the fastest, according to a new report.
The study, from Forrester, made estimates of all digital advertising spend; including search, display, social and email, to arrive at the $103bn figure, marking a large increase from $57.3bn (£35.7bn) posted this year.
The rise would mark 12 % compound annual growth rate over the next five years, taking its share of total ad spend to 36%.
Search marketing will continue to be the largest ad revenue data in the sector, with social media the fastest growing element.
Mobile will account for 66% of interactive spending growth over the next five years with investment in mobile tablet and search, display and social reaching $46bn (£28.8bn) by the periods end.
In its Forecast Forrester projected email marketing to hit $3.1bn, up from $2.1 billion this year with social Media rising to $17.3bn from $7.5bn.
Elsewhere display advertising will reach $37.6bn, up from $19.8bn search marketing will attain the heady heights of $45.4bn, growing from $27.9bn this year.