And for another anecdote, I've never not shipped with USPS and I've never had a problem with them.
I would never ship something worth more than a hundred bucks or so without insurance. Signature confirmation probably would've helped you out here as well. That's definitely something to think about next time you sell something worth a lot of money.
This. I ship over 1,500 packages a year. At least 98% of them go via USPS. I think I've lost about one package a year. All of them went to apartment buildings and were presumed stolen. (I do insure all shipments over $100.)
To answer the question, my shipping policy clearly states that I own the package until that delivery confirmation barcode is scanned. At that point it belongs to the recipient. I can't be responsible if it's stolen or lost before they get it, and in fact I have only their word that they did not.
This is the advice I give people who claim they didn't get a parcel that was confirmed delivered:
After a package is confirmed delivered, or when you are notified of a delivery attempt, that package is no longer the responsibility of Curio City. We can't be responsible for packages that are lost or stolen after they're confirmed delivered. Our ownership of that package ends when your carrier scans the label to prove that the package was left.
What can you do if your shipment is lost despite being confirmed delivered? First, ask anyone else in your household if they might have brought it in (you would be surprised how often this turns out to be true). If you live in a multifamily unit, ask your neighbors (even if you think someone might have stolen it, they might return it out of guilt!). Second, check the area surrounding your mailbox or front door to see if the box or envelope might be in a concealed spot. Third, ask your carrier if s/he remembers where he or she left the box. Finally, if none of those steps pan out, take your delivery confirmation number to your local post office and ask them to search for the box. Sometimes a postal carrier scans the label while the box is still on the truck, but neglects to take it to your door. In such cases the box will turn up either on the truck or in the loading area.
To prevent future losses, make sure that your carrier knows where to leave packages securely (especially if you live in an apartment building). If you don't have a secure place to get packages, have your order sent to work, or to a neighbor. If you are shipping your order to somebody else, be sure to tell them that it's coming. As much as we hate to hear about packages that are stolen or lost after delivery, we can't do anything about them. Insurance does not protect you against theft after delivery.
Bottom line is that you can't do anything about it if a package was stolen after delivery, and that's almost invariably what happens to those that go missing. I don't know how ebay looks at things because I don't sell there anymore...but delivery confirmation should get you off the hook.
BTW, if you're a frequent seller you should have a written lost package policy to which you can refer people who make claims against you.