This old advice is given in the bible, by a man called Jesus. You can look it up in a book called Matthew, chapter 5. The moral was: if you do something good, don't let everybody know it. If you tell everybody how good you are, God wont reward you, as you will already have gotton your reward from the people around you.
Sometimes I see the same effct in organizations, but not on purpose, but by accident. Some call it lack of communication, some call it lack of coordination. The bigger the organization, the easier it is to forget to communicate something essential. One department invents something cool, but it remains a secret, known only within the department.
One nice example of lack of communication I discovered today in livemail, see this pic. For those who dont know dutch, the message in the pink background says: This message has been blocked for your safety.