jwolthuis - 4:24 pm on Mar 12, 2012 (gmt 0)
I have found that ...
I'm surprised. Our flat-rate volume accounts for maybe a couple percent of our Priority shipments (very heavy items only).
The Regional Rate "A" boxes account for +90% of our Priority shipments. They are cheaply-made, but we pack them well (kraft paper is cheap).
I give credit to the guy who invented the "flat-rate" concept. Whenever I go to the post office (maybe once a month), they are lined up to buy those flat-rate boxes. Who cares if the postage is double the regular Priority Rate. If it fits, it ships!