Tim O'Reilly: The Myth of Internet Time.

And the other thing is this: No matter how smart you are, no one knows for sure what works and what doesn't until it's tried in the real world. Adjusting as you go is a natural component of virtually any endeavor—from learning to walk, to flying a plane, to, yes, figuring out a new business. So companies that tried to ramp up in record time have a disadvantage to those who start smaller, which is similar to what startups enjoy versus larger, established players—i.e., they can't adjust as fast and try as many things. They have a lot more risk riding on their first guesses. Of course, this didn't matter as much back to those for whom getting big (in head count, anyway) was the definition of success.