Frank was on the "rich people beat" for the Wall St. Journal (iirc), which apparently involved following them around and writing about their wacky habits. While working this unusual job, he had the realization that, with the numbers of extremely rich people exploding, they were creating a whole separate country for themselves (thus the title).
It's an intriguing premise and I don't want to go too far into it here, but he knows how to support his book with anecdotes and a couple charts.
But that wasn't the most interesting part of the book is actually the first chapter, which focuses on an elite school designed to train household managers (aka butlers). Reading quotes from those students about their "service heart" and how wonderful it is to anticipate someone's needs and totally care for them was like reading about a village of Martians. really weird and interesting.
The other interesting fact was how few of today's rich actually inherited their wealth (for people with liquidity over $25 million, the figure is, like, nine percent). A great many of them hit the big time with a "liquidity event"--which usually means they sold their stock/company/both to an investment firm for a criminally huge amount of money.
Apparently, people all over the world (except the U.S.A) save most of their money, which has created a "river" of money searching for investment opportunities. Frank doesn't specifically say whether the size of the river has created these monstrous payouts, but that's definitely the impression I get.
So you have all those tech start ups. And you have the guy who worked like crazy to build a huge swimming pool toy company that he cashed out for hundreds of millions of dollars. And you have the guy who started a business selling ceramic villages (little houses and fire stations and such) with lights inside that he sold off and now lives in a five-story Manhattan penthouse. Some of the ways these people found their way to Richistan is pretty absurd (which is how they got into the book, 'natch).
The rest of it was pretty much what I expected, even the parts that surprised me. Of course all the super-rich think of themselves as basically middle-class folks with a couple extra bucks. Of course none of them feel that the have enough money, no matter how many zeroes they have on their bank statement. Of course they surprise me by the expense of their toys (which is how I expected to be surprised). One yacht isn't enough, people! You need a second "shadow" yacht to follow the first one and carry all the cars and helicopter and such that you will need on your island vacay. And why not buy a double-hulled landing craft so you can drive your Land Rover right up the jungle beach?
I picked it up because I write about rich people often enough in the Twenty Palaces books, and I wanted to make sure I had all the most recent skinny. I found a couple useful tidbits, but generally it was a quick, amusing read.
For a followup, I picked up The Black Swan: The Impact of the Highly Improbable by Nassim Nicholas Taleb, but this one's going straight back to the library. It's not just that I dislike his writing style (and I do). It's that I dislike him. When he got to the part of the book where he said "If you picked the heaviest biologically possible human on the planet (who can still be called a human),..." I knew I was done with him.
They don't stop being human just because they become fat, you fuckwit.
Now I have nothing to read on the bus ride home, but that's preferable to another page of that book.