Progressive disclosure defers advanced or rarely used features to a secondary screen, making applications easier to learn and less error-prone.
Jakob NielsenEven better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
Jakob NielsenUltimately, users visit your website for its content. Everything else is just the backdrop.
Jakob NielsenOn the Internet, it's survival of the easiest.... Give users a good experience and they're apt to turn into frequent and loyal customers. But ... it's easy to turn to another supplier in the face of even a minor hiccup. Only if a site is extremely easy to use will anybody bother staying around.
Jakob Nielsen