The quality is just not as good yet.
This may be the reason streaming only works much better. In fact that's the first thought I had, "I wonder how they are going to deal with the Canadian mail system."
This seemed to vary by province/region. I remember some towns way out east having only a few phones (in the local store). And I remember thinking, "wow, and we think the Midwest is isoloated."
There are some postmen with suspiciously great DVD collections out there.
Postal service has always been good for; depends how far back you're talking.
Having said all that, why bother setting up the logistics required to ship DVDs when you can just stream them to a population that is heavily wired and internet literate.
Rates, delivery times, etc.
$0.57 Nationally
$1.00 To the United States.
The delivery times vary from a single day to week, depending on the destination.
I do not believe that Netflix will ever ship dvd's from the states as Custom's Brokerage fees are quite high.