You catch a ball or you don't. You hit your target or you don't. You catch the ledge and save yourself from a fatal fall, or you don't. As Master Yoda would say "Do or do not, there is no try.".
In business today it is more important than ever never to settle for "good enough". Why? If we don't constantly strive for greatness in whatever we do, someone else out there will. And in today's socially-connected world, your customers will find them and love them for it.
Today, 'good' just doesn't cut it. Anything less than 'great' is failure.