• Aesthetics
Making something look good will make the time your users spend
using your application more enjoyable; and happier users can only
be a good thing.
• Efficiency
Time is money, and a great interface should make the user
more productive through shortcuts and good design. After
all, this is one of the core benefits of technology:
• Forgiveness
Everyone makes mistakes, and how your application handles
those mistakes will be a test of its overall quality. Is it easy to
undo actions? Is it easy to recover deleted files?