I think the Olympic Games are very important for the city organises them.
It's an international event, for that reason around the world the people know an speak about the city where they are celebrated.
203 countries currently participate in the Olympic Games, around 3.8 billion viewers watched the games on television and in Sydney 2000 there were ower 16.000 broadcasters and journalists. During de games the city where they are celebrated is "the centre of the world".