Digital advertising spend (on search, display, social, and email) will top $103 billion in 2019, up from $57.3 billion this year. This represents a 12% compound annual growth rate over the next five years, and will equal 36% of all ad spend in 2019.

Search marketing will remain the largest share of the overall digital mix, but social media will experience the steepest growth. Specifically, by 2019 Forrester forecasts the following spend:

  • Email marketing: $3.1 billion, up from $2.1 billion this year.
  • Social media: $17.3 billion, up from $7.5 billion this year.
  • Display advertising: $37.6 billion, up from $19.8 billion this year.
  • Search marketing: $45.4 billion, up from $27.9 billion this year

This year, Forrester has baked mobile into its ad forecast — representing it as a deployment option rather than a channel. However, it’s worth noting that mobile accounts for 66% of the growth in interactive spend over the next five years. Investments in mobile and tablet search, display, and social will top $46 billion by 2019.

Finally, while Forrester predicts that interactive marketing will overtake TV advertising by 2016, its pace of growth will start to slow thanks to improved attribution measurement and a shift toward contextual marketing.

To learn more about this forecast, visit the Marketing Leadership blog here.