The USPS is going broke,or are broke due to the various reasons Mike mentioned and the future in shipping lies with Fex Ex,UPS,DHL,etc... Their rates are all over depending on if you are commercial,residential,if you have an account but what I get is a solid,never fail delivery system. I have had items shipped from California to New York and was charged $5, cannot figure it out but there you go. Never had a shipment lost and if they day 2 days or 5 days,it is that.
Or from Montreal to Vancouver for $12 by UPS.
I ship all my work related materials by courrier,rarely use Canada post except for local letters.
I can tell you I will not pay $10 or $15 to have 1 CD shipped. I have already gone the FLAC download route.It is just the way it is.Hard copy product of music,or even DVDs and books is on the way out.