A nice article by DJ Patil, a data scientist who used to work at LinkedIn, in wired.co.uk.
Now it’s easy to say go forth and fail! What’s most important is how you fail. The best method is to fail fast. LinkedIn wasn’t the first social network in a very competitive space nor did we know exactly where we were going. It was an extremely tough fight. What allowed us to succeed was our mantra of failing fast in order to survive. We would build products quickly, test them out, many of them failing, then learn about went wrong and try again.