Makes me laugh. Air NZ have just released their latest brainwave for domestic passengers...you will be charged for the number of bags you check in. First one is free, second one is (say) $20, the 3rd and subsequent ones $30 each......but the one free bag can weigh up to 30kg. Effectively they want to reduce the number of bags people check in to save time, but in doing so have actually financially induced people to have heavier single bags.
Don't tell the Air NZ loaders that anything over 20kg is too much...or maybe the "big boys" they use (especially the Mangere locals in Auckland) are a bit stronger than their Aussie counterparts?