title: When should I use attribute in C#?
body: <p>I saw some of the examples of utilize attribute, e.g.
  (as a map for dynamic factory)
  <a href="http://msdn.microsoft.com/en-us/magazine/cc164170.aspx" rel="noreferrer">http://msdn.microsoft.com/en-us/magazine/cc164170.aspx</a></p>
  
  <p>Just wondering what is the advantage of using attribute?
  I can find the reference on <a href="http://msdn.microsoft.com/en-gb/z0w1kczw(VS.80).aspx" rel="noreferrer">http://msdn.microsoft.com/en-gb/z0w1kczw(VS.80).aspx</a>
  however, I am not sure when and why should I try to use it.</p>