I use MacUpdate Desktop to keep my non-Apple apps up to date, & my subscription (a quite reasonable $20 per year for up to 5 Macs) expired. Time to renew! I headed over to https://www.macupdate.com/members/renew/, chose Credit Card, and filled in the form, & pressed Renew, only to get this screen:

Here’s a close-up:

For state, I had entered Missouri, but that was wrong. I should have used the two letter abbreviation MO instead, but nowhere on the form was I told that until after I pressed Renew. That, my friends, is really stupid.