I just had an experience with an eBay customer that led me to attempt to divert a very small amount of money to charity.
The customer (in a place called Mudchute, believe it or not) bid on two of my comics auctions that were ending about one day apart. After the first one ended, he paid me instantly through PayPal. I noticed that he was still the winning bidder (for 25 cents!) on the second auction. I emailed him, asking if he wanted me to wait and see if he'd win, or go ahead and send out two shipments if he did win.
Of course, somehow he hadn't realized that he had bid on two auctions from the same seller, and elected to wait and see.
It came to pass that he won the second auction as well, for the opening bid of 25 cents. The extra weight of the second auction wouldn't increase the shipping cost at all, so 25 cents was all that was owed. I wasn't about to ask for payment thru PayPal, because their transaction fee would have been greater than the amount sent. And having to wait for an airmailed payment from Mudchute in Merry Olde England seemed a little absurd, as well.
So I told the chap to put a coin in a local animal shelter's collection tin next time he was in a little store somewhere, and we'd be even.