I don't think we need 6 day delivery. I really don't think we need even 4 day delivery. Mon/Wed/Fri should be enough. There used to be a time in American history where people were expected to go to the local post office and check if they had mail. With USPS tracking, people could sign up to get mail waiting emails or voice mails. Then, if the mail was important enough, they could go and pick it up or wait for the next scheduled daily delivery. Would provide a vastly more efficient system in the long run I believe.