It was very interesting! It's a story from Michael Fazio, who worked as a concierge at one of the most exclusive/expensive hotels in New York. However, it also had several good business/economic concepts.
1. Discusses how there are benefits from trade. Those who used his services often could not obtain the product for a similar price. Michael went through an example where he would get a product for $300, the client wouldn't have been able to obtain the product for less than $500, and he charges $400. Each side gains $100.
2. Entrepreneurship! The author changes careers and also thinks about new business opportunities. He does a really good job thinking through and explaining how his previous opportunities and training have prepared him to go into new business ventures. He describes the ones that work and the ones that don't work. I found this very enlightening and fascinating.
3. Human capital. The skills he acquired from his early jobs clearly helped him develop skills that allowed him to succeed as a concierge. Economists call this human capital - which can easily be acquired in most jobs. (As a side note: part of the reason I'm so opposed to minimum wages is the high teenage unemployment has a devastating affect on their human capital acquisition - which decreases their future earning potential.)
Outside of the economics, it was still extremely interesting. There are many anecdotes, from bathtub issues, to guys who bring suitcases of money, to cases where men try to hide their newly earned STDs from their wives. Sometimes a bit sleazy, but all very interesting. This book is both fun and educational, and it's always great when an entertaining story contains many examples of economic principles.