Influencer marketing is projected to grow from US$2 billion revenue in 2017 to $20 billion in three years. Who are the influencers? What is the influence industry?

Joel Backaler Discusses Five Trends Driving Influencer Industry. Joel Backaler is the author of "Digital Influence: Unleash the Power of Influencer Marketing to Accelerate Your Global Business" published in September 2018 and available on Amazon.com