The book he mentions explains why Facebook and social networking sites work as well as they do. Have you ever wondered why Facebook never invites you to be friends with someone, its always "Your friend thinks you might know.." Just the tiny change from saying "You might know..." to "Your friend thinks you might know..." makes a huge difference. I encourage anyone to read the book, because it has huge implications for marketing and start-ups. It explains a lot of why things work the way they do, why people like Apple, why people are encouraged to buy, or discouraged. Its a dry read, but invaluable.

It will even tell you how to monetize Twitter... :)