"How do you know you're a big company? Answer: When everybody thinks you are. You're a small company when everybody thinks you are, including your employees. You're kind of an emerging company when everybody thinks you are. You're a larger company when everybody thinks you are."
This has implications for HR strategy, as Ballmer eloquently explains.
"We hadn't renewed our employee value proposition, if you will, since we became a big company. ... Clearly something happened between 1999 and 2003. We went from being whatever we were to being viewed as a very big company, because governments and everybody else said these guys are a very big company. And then you have to say, O.K., if that's the perception, then you have to have a value proposition that's appropriate. And not only had we not renewed our value proposition, we had tried to make small tweaks in some of the trappings and form around that value proposition that were sort of inconsistent with where it was and where it needed to go."
Source: Reshaping Microsoft's HR Agenda (BusinessWeek, Sept 10th 2007) via The Secret Diary of Steve Ballmer