"Social media sites tend to foster consumer interaction and, during a time when capturing the attention of the consumer is so critical, it is no coincidence [that] we are seeing social media drive [advertising] revenue. Ripe with various formats primed to take advantage of future technologies, revenue derived from advertisements on social media sites is expected to continue to grow in the future."

-Commentary from the IAB internet advertising revenue report (2018 full-year results), prepared by PwC (May 2019).