The biggest problem with The 4 Hour Work Week is the math, you see the entire book is just built on this faulty premise: a 10 cent PPC or Pay Per Click.
When you start to add up how many impressions you would get from such a low PPC you would need keywords totally in the hundreds of thousands per month to get hundreds of clicks per month. Then with a conversion rate of a generous 2%, you might get 4-5 sales per month.
To really make anything meaningful you need to have a PPC between $0.75 and $1.00, but at these cost you only really get profitable at over $100 profit per sale, this is because your advertising cost per sale are between $75~$100.
So while I loved the book, I wish I would have read this PPC assumption before I had to figure it out by spending a few hundred dollars…