So I bought the book and many months later actually read it. Cialdini was researching the topic of compliance and to best understand how compliance professionals worked, began answering ads for different types of sales professionals to learn their methods. After gathering a wealth of information he classified his findings into six basic categories in which a psychological principle tends to direct a certain behavior.

1. Reciprocation

2. Commitment and Consistency

3. Social Proof

4. Liking

5. Authority

6. Scarcity

While these principles may sound familiar, Cialdini supports them with real-life examples. What I found particularly interesting was the relation of the date a suicide story was published to subsequent monthly suicide rates and even airplane and car fatalities. It sounds morbid but it helps emphasize the degree to which these principles hold (in this case, social proof).

Cialdini also includes a 'How to Say No' section at the end of the chapter, effectively making the book a sort of manual on how to deal with the tactics of what he calls 'compliance professionals'. As with most things, being aware of the causes of resulting effects helps us deal with relevant situations more effectively.