Eco dogfight: UPS says it's way greener than FedEx

Not too long ago, getting a package to arrive overnight was a good enough marketing claim to win over customers. But in this era of sustainable business practices, everyone from Wal-Mart (WMT) to Walt Disney (DIS) is burnishing their eco-cred in the hopes of coat-tailing on the current green ethos.

The green factor increasingly plays a role in customer decisions. Which is probably why package and shipping giant United Parcel Service (UPS) has come out swinging against arch-rival Federal Express (FDX). The two mega-brands have been locked in a public dogfight over who's green cred is more legit and which company is actually running a more sustainable operation.