Influence: The Psychology of Persuasion

Cialdini's six principles of persuasion, being reciprocation, commitment and consistency, social proof, liking, authority and scarcity. Each gets a chapter explaining the mechanism, the conditions under which it works, and how practitioners deploy it. Written from field research among salespeople and fundraisers, which makes the examples concrete. Read alongside Hooked for the overlap between persuasion and product design.