Delta has its DASH service, Northwest had "VIP (Very Important Package)" service.
Back in the days of NWA, VIP was MUCH more user friendly. You could even book and ship VIP packages at a NWA checkin kiosk, and it would create a tag at using the bag tag printer for the agent to affix to the package.
Delta has come a long way from where DASH was a few years ago, but they have nothing like VIP. Delta Cargo just launched a new website recently however, which is a big leap over the old one.