OK, the "overpayment" scam is clear enough. Not a lot of people know that with foreign cheques there is no defined "cleared" date. They are paid in "for negotiation" (or similar) and can take months to clear the system (or bounce).
These African customers I had were going to pay with a credit card. OK, again, a stolen card, so the payment will be withdrawn by our CC provider. In the meantime, we would have despatched the goods. But what the hell can the scammer do with something really specialised? That's what I don't get.
But then there are kids who will smash a car window to nick a car radio front, worth £10 in a pub, which is useless to anybody and everybody knows it. I had that done... quite pointless.
Incidentally, Paypal isn't so good either. You don't get an irrevocable payment via Paypal. If the buyer contacts Paypal and says he never got the goods, Paypal will take the money back out again. You can't really communicate with Paypal. They got "done" by the FSA for not displaying a contact phone number; they are a "minimal customer service" operation which is OK all the time things are going smoothly. If they got half a chance they would wash their hands of any customer communication altogether. That's why one must always send stuff with a trackable service and get a signature (not Recorded Delivery; postmen often deliver those without collecting a signature, and there is no tracing en route).