I had a credit card that was closed for inactivity. It had a $5 credit on it for going to electronic statements. So every month, I would get an email saying that it had $5 credit on it. After seeing this thread, and getting yet another email, I decided this was stupid, and to tell them to keep the $5 in return for not emailing me about the $5 credit I had for a card that I couldn't use.
After about 10 minutes on hold, I explained the situation, and they're mailing me a cheque for $5. Win-win.