Seller Impact Of Items Not Received

That impact is largely dictated by how the seller handles the situation. If a seller stonewalls and blames it on USPS, claims he is not responsible, and refuses a refund, the impact will be large in terms of negative feedback and DSR ratings decrease. With no proof of delivery, PayPal will yank that money right out of your account and send it back to the buyer. If the seller is very cooperative and insurance and DC were used, the seller will only be out shipping fees and should get good ratings and FB. If no insurance is used, the seller loses completely and there is nothing that can be done other than issuing a refund to the buyer.

How you package a coin makes a big difference as well. Properly packaged coin will usually not have problems while improperly packaged coins can slide around potentially breaching the envelope. Coins dropped into a 1st Class envelope with nothing more than a 2x2 tend to have the most problems. The movement can split an edge and being run through automated cancellation can also jam the envelope which can damage the coin. I use 1st Class envelopes for inexpensive coins but the coin is in a 2x2 contained by a self sealing rigid foldover cardboard mailer. The rigidity renders the envelope nonmachinable so it needs to be hand cancelled and treated more gently. USPS charges a 20 cent surcharge for this treatment(64 cents total for 1 ounce). I have mailed a couple hundred coins in this manner without a single loss. Anything over $75 or so gets a bubble mailer and Delivery Confirmation.

As a seller, I cover myself to the maximum extent possible in the shipping process, because that's where I get my remedy if the package does not reach the destination. I insure; I use delivery confirmation; I get a return receipt of the value is over $200 (I think the USPS requires signature over $250 anyways).

I will go to the effort of video-recording my packing process for stuff $500 and over, to prove to USPS that I sent exactly what my insurance claim says I sent.