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This is a highly researched book. I found some of the language old and a little difficult to read. However it is worth reading to understand many of the things that affect our decisions especially from external forces.
If you have any previous knowledge of social psychology, most of this book is probably going to be way too basic for you. Some nice discussion of how to counteract influence methods, but all-in-all I felt like I'd seen 90% of this book many times before.