My rating: 4 of 5 stars
This main point of this book is the principle of “failing fast.” Since you don’t know everything (and a startup knows very little), it is most efficient to quickly create some data to base decisions on.
The distinction between “vanity metrics” and real, useful metrics is illuminating. A “vanity metric” shows something that looks positive, but does not answer the question you need answered. You need to decide at the beginning (before releasing your first release) what data you need. For example, a vanity metric would be total, accumulated downloads – guaranteed to never drop! A useful metric would be conversion rate to paying customers.
With a quick-and-dirty product (the “minimum viable product”), you can start gathering data. There can be three results:
- Your idea is hopeless and should be abandoned. Next startup, please.
- Your idea is seriously flawed. In this case you do a “pivot” where you change your product dramatically, release a new product and measure again.
- Your idea is promising. In this case, you persevere, make some change you expect to improve your core metrics, release a new product and measure again.
The use of the word “lean” in the book is a bit of a misnomer. While the book keeps referring to manufacturing practices, it does not advocate elimination of waste as lean does. It only talks about elimination of waste in one dimension: Eliminating the waste of building something nobody wants.