But unlike the financial numbers used to evaluate more mature companies, the so-called "vanity metrics ... competitors," Eric Ries, who is the author of the book "The Lean Startup" and has ...

Eisenmann, Thomas, Eric Ries, and Sarah Dillard. "Hypothesis-Driven Entrepreneurship: The Lean Startup." Harvard Business School Background Note 812-095, December 2011. (Revised July 2013.) ...

Eric Ries, author of a very influential new book, The Lean Start-Up believes entrepreneurs measure the wrong things, leading them to make the wrong decisions. He talks to WSJ's Ben Rooney.