Writer, geek, dad.
I've read a lot of business books (and also written one) and this is the best I've seen in a long time. It could just as easily have been titled "The Scientific Startup" but I guess that might have scared people off. It outlines a scientific method for planning and running a startup that prevents costly errors and ensures the entrepreneur(s) learn enough about their business and the market in which it operates to decide their next step. It's essentially about running sequential experiments testing the fundamental assumptions about the business (eg "will customers buy this?") in the quickest, cheapest and most effective way so the startup is a learning organisation (indeed that, rather than the pursuit of money is the point of a startup according to Ries).
This is the first book I've ever listened to, bought on Kindle and then bought the paperback so I can scribble. There's plenty of hyperbole around when it comes to business books but this is a radical, and much needed, shift to the way startups are run. First class.