Contagious by Jonah Berger is a great read for anyone into marketing, influence, or the psychology of consumer behavior. It explores what makes people share. In other words: why do certain products, ideas, or content 'go viral'? A lot of research is simplified into 6 key principles: social currency, triggers, emotion, public, practical value, and stories.
Pre-Suasion shows a new side of influence. It's about everything that happens BEFORE you ask someone to say yes to your proposal. Professor Robert Cialdini has distilled hundreds of scientific studies to prove that how you FRAME a message from the beginning is crucial to its success.