I think my boss (well, my CEO, not my direct supervisor) may be responsible for that. I was told that he was the one who came up with "bulk presorted mail." Basically, he went to the post office and convinced them that since the postal carriers were going on those routes anyway, a few pieces of extra mail wouldn't affect things significantly, so give them a better rate. Thus, they would presort the mail for those routes and got a cheaper price for it.