Chuck Martin writes in the July Darwin Magazine, Information Sharing: It's all about what you know - and what you choose to tell others.
In a survey over a base of 2,000 executives and managers nationwide, NFI Research also found that the smaller the company, the more information was shared, and the more relevant it was.
This fits with other ideas about community and how people work together. There is that critical organization size (~150 people) beyond which there is no hope of knowing everyone in the organization. I had a conversation the other day with a gentleman at a company which has grown to ~100 employees and which regularly talks about their growth strategy because they know that they will soon hit that magic wall. He also said that there are built in organizational changes as companies grow from 25 to 50 to 75 people as well. These changes are sure to impact how people share, so it is best to plan for it in advance.