Answer:Diffusion
Step-by-step explanation:
Diffusion refers to how a new technological innovation or idea in the market is spread out and accepted by the customers. Diffusion means the information about the newly released products spreads from one consumer to another.
Diffusion depends on how customers feel about the released products like in this case Kevin bought the new smartphone which he was probably happy with that he shared with his friends who were convinced enough to buy it and tell their friends too.
This can be said to be paper of the word of mouth.