How I (almost) got scammed on eBay
A couple of months ago, I purchased a huge lot of retired stamps from Stampin' Up! and started selling off the ones I didn't want to keep. After exhausting the members of Splitcoast, I tried my luck on eBay and have done fairly well - only a handful of stamps left to sell (which I'll be posting in my Etsy shop soon).
I put up two large lots of stamps, and one buyer snatched them right up. He had over 15000 positive feedback, so I packaged everything up per Paypal's address and his instructions, got delivery confirmation on them, and sent them off. They were marked as delivered and all was well.
I'd also emailed him the tracking numbers through eBay's system three times with no replies, added them to my eBay listings, and also added them to the PayPal transactions (a MUST!). Thank goodness I did that - it ended up saving me in the end.
This buyer, three weeks after the items were delivered, claimed non-receipt, and filed a dispute through PayPal, which put my account on hold for $199.99. Meaning I couldn't take any receipt money from my Etsy sales out of my account, because it was in a negative balance. He claimed he didn't receive one of the packages.
I replied, added copies of the tracking/delivery confirmation to the dispute, and escalated it to a PayPal claim. He didn't respond, and it had been a couple of days. I called PayPal today, more to just find out what the process was (how long he'd have to reply, whether my evidence would ensure my seller protection) and the amazing person on the other end looked at the delivery confirmations, looked to make sure I'd followed all PayPal's requirements, and closed the case in my favor right then and there!
A Google search on this buyer told me that he's claimed non-receipt in other listings as well, though none of those forum posts said whether the issues were resolved in the buyer's or seller's favor. As mentioned, this buyer has over 16000 feedback.
If something looks fishy, do a google search on the username. I wish I'd done this prior to shipping out the item. ALWAYS ship with a tracking number (preferrably through PayPal because it's all done for you, but at least with delivery confirmation, and make sure you add this number to your PayPal transactions so PayPal has it in case of a dispute. And did you know that anything over $250 requires signature confirmation too? I didn't know this!
From my experience, escalating the dispute to a claim and then talking directly with PayPal, playing nice and asking for help, got my case resolved. I've read in some cases that waiting for a buyer who never responds can end up in the buyer's favor - whether this is true, I can't say. And always ship to the confirmed address on the PayPal transaction. I've read that the buyer could charge back their credit card and then you could be SOL as a seller, so best to act fast.
This is just my experience, I can't speak for every transaction or dispute, as I don't know their circumstances. But follow all the rules as a seller EXACTLY, and then your seller protection should work for you.