Start-ups rely on execution

People often assume that once you have the idea, all is plain sailing. Yet many failed start-ups were based on good ideas (which often succeed in other hands). What made Facebook succeed where Friendster and Tribe did not, or LinkedIn where eCademy or Ryze did not, was the right execution. This does not mean that all went smoothly. A lot of scrambling went into the success, and a lot of quick recovery from mistakes. Yet, all too often, execution is underestimated and the value of the idea is over-estimated.