The Mission Statement

What is a mission statement and how does it help a business to prosper?  How does a mission statement relate to a businesses' goals?  Are they even necessary?
Read several mission statements from the list found at: http://www.missionstatements.com/fortune_500_mission_statements.html

Then analyze three statements and give your opinion of each based on the following:

1. Does it apply to this specific business or is it more general?
2. Does it tell you "what this business is about"?
3. Is it impossible to disagree with or analyze?
4. Does it provide any specific detail?
5. Does it provide any vision of the future?   

Choose three companies - analyze their mission statement using the above criterion - include one picture for each statement.