Case in point.
About 10 years ago I sold a rare record of late-1960s electronic music to Richard James, and made the mistake of shipping it to him (all the way to England) before he paid. (weird coincidence, on about the same day I sold records on ebay to "Richard James" and "James Richards" and just looked at my handwritten list of money received and foolishly sent it on)
He was slow to pay, surprise! and by the time I got around to please asking him to pay up, he already had the record in hand. He basically told me to piss off.
After several ugly emails back and forth, he finally paid up after I noted a very small identifying sticker on the LP itself. I suppose that he realized that I was right and he owed it to me. Good thing, it was a $100 record!