Why Name Brand?

I have never understood is why people need to have name brand things?  What purpose does that serve in your life?  You are just spending more money on something that you don't need to spend that much money on.  Who cares if your glasses are Oakley, Ray Ban, Saks Fifth Ave, or Bebe rather than Joe, Candies, Michael Stars, or Durango?  That is something that I will never understand.  But I guess showing off your money is important to some people.  Oh well. . .