Purple Cow was published in 2002 when TV ads were the norm and FaceMash a year away from being conceptualized in Mark Zuckerberg's college dorm. Seth argued that that while industry giants could still get away with marketing the same old products through sheer volume on TV, small companies looking to launch the "next big thing" could no longer use the same playbook as before. The math doesn't add up and for everything that people want, there has already been a "first".
His book submits that advertising itself is no longer good enough. Rather, the product needs to lead the charge; it has to be something worthy of breaking through the noise.
Surprisingly, in a very Netflix's Dark-type of way, Purple Cow feels as relevant today as it was 20 years ago, since every ad I see scrolling through Instagram feels the same. Concepts that break through the noise need to live on the fringes— Liquid Death (canned water with "metal" branding) is just a modern day Hooters.
The book is a great reminder of how marketing should be. Yet, iterations and regurgitations of Seth's seminal thesis has left my first reading of the book... a bit of a let down. Through a two-decade game of telephone, I feel like I've heard it all before. At times, the success examples felt like a scatterplot of random anecdotes suspiciously looking like survivorship bias (how about instances of Purple Cows that didn't succeed... and why?)
TL;DR: Purple Cow is a great and brief reminder of what marketing should be: led by the product itself.