We always used to leave feedback first for our customers & couldn't understand why other seller's didn't leave feedback first. Until we got our first negative which simply said 'item never came?'.
After 7 1/2 weeks since postage, why wouldn't you contact the seller to ask where your item is? Now we won't leave feedback first so we can ensure the item has reached it's destination.
I don't agree that seller's are responsible for item's once they are posted - I've had stuff go missing that I've sent to family & I know people who have worked for Aus Post & seen theft firsthand. How are we supposed to prevent that without registered post?