Are you familiar with Influencer Marketing?
I am. It's when famous people are more the message than what they want to sell.
Exactly! It was completely found from personal influence.
I love the testimonies that people give from buying the product. 
I believe the testimonials from customers are basically configured based on how well the seller influenced them they needed it.
Have you read the books Personal Influence and The Effects of Mass Communication? 
I have not, what are they about?
They just give more information on the idea of influencer marketing.