He discuss following universal principal of Influences:
1. Reciprocation : We always reciprocate with gifts / favor we receive.
2. Commitment / Consistency : We tend to keep our promises and tend to keep our consistence perception in mind of others.
3. Social proof : We tend to look around and be a part of crowd to make easy decision making.
4. Liking : If we like people we get easily agree to him/her even if they are wrong.
5. Authority : We feel a sense of duty or obligation to people in positions of authority.
6. Scarcity : This principle says that things are more attractive when their availability is limited.
You have to read and understand many concepts, hence it was not a easy read. It took me more than 20 days to read this book, but it was worth it.
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Check out video below for understanding this principals.