A few people have emailed to ask, "Where do we put in our secret codes?". Well, unfortunately, Paypal doesn't offer a completely obvious way to add codes. So, I'll try to explain it as best as I can.
After you click the "Pay Now" button on the episode posting, you'll be taken to the Paypal site. Once you've logged in and told them you do/don't want to take advantage of their credit deal, you'll come to a page that looks like this:
At least on my screen, the special instructions box at the top appears. See that tiny little "add" button in blue? Click on that to write down the podcast episode number and the two secret code words. Once or twice I've seen the same text on the bottom half of the page, but it should still look pretty similar.
And, of course, if you ever forget to add the information, you can always email us at firstname.lastname@example.org with the codes.