This is the core concept behind the book. Your offering must be remarkable, just like a purple cow. You can no longer rely on advertising on a marketing department to simply selling existing products; you must innovate and focus on the product itself.
The method he argues for is to create remarkable products that people seek out. He calls such a product an "idea virus" that you must get to the right "sneezers" who can spread it. These sneezers are early adopters in a specific market niche that you directly appeal to. After you've had success doing this, you must reinvest your profits to create new remarkable products as the existing ones become commonplace.
He argues that you should welcome criticism and in fact do things that provoke it. Appealing to the center of the market and the masses is bad; you appeal to no one and your message becomes bland. He argues for the opposite. If you show up in a parody, you're doing the right thing.
He brought up the Japanese word "otaku," which means something more than a hobby but less than an obsession. You must find consumers with otaku who will try your product, learn it, and spread word about it. It is helpful to target markets with already existing otaku. For example, go to sci fi conventions to find sci fi fans.
The key is to change the product, not the ads. A slogan is just for sneezers to pass on your idea properly. Don't use committees or compromise on your crazy, directed ideas. Leave design mavericks alone to do what they want and create remarkable products. Once you get sneezers, get their permission to keep them posted on progress, and give them tools to spread the word. If you can, build marketing into your product directly so it's obvious how to...