Chit-chatting about holiday preparations with someone, I mentioned that I had to start on Christmas cards tonight. "Oh, you do cards? I love to get them, but it would drive me crazy to have to send them." "But you have to pay it forward!" "Nope. Doing cards would drive me crazy. But I do love to get them."
You weren't on my list to begin with, but if you were, you'd be cut. Not getting a card back from someone you've sent one to is the easiest way to cull the list.