The bottom line: A true classic on decoding the purchase process, but why pay anything when you can get it for free?
The first thing anyone should know is that Why People Buy is available for free in a myriad of formats here: https://archive.org/details/howtopredictwhat00ches
I learned of this book after reading Gerber’s The E Myth Revisited. There the author makes a few references to Why People Buy to illustrate how color and packaging provide unique unconscious triggers to “activate” the buy reflex.
The book begins by describing the four pillars of successful marketing and then moves along by detailing different factors that play a role in the consumer purchase process. For example, Cheskin discusses unconscious motivators, the meaning of color, package design and color, and the necessity of quantifying reactions to your advertising.
The book is a quick read, straightforward and very easy to understand. A large emphasis is placed on color that is still relevant now as it was 60 years ago. Yet, it becomes very clear from the book that Mr. Cheskin had a significant collection of market research that was made available for purchase. So, in many of the chapters, the writer stops short (and sometimes quite a ways off) of giving specific information with the hopes that you would then take the next step and contact the Color Research Institute.
If for nothing else, what you will come away with is a basic understanding that people do not tend to buy based on rational, comprehensive and complicated algorithms; instead they really are quite reflexive and simple, and how you present your product has a lot to do in stimulating that reflexive buy trigger.
The major reason why this book is rated with three stars is because of the current sticker price. Although some of the information is valuable, I fail to see why that price is assessed so highly ($250 as of March 2015).
Dr. C. H. E. Sadaphal