"Be kinder than neccessary; for everyone you meet is going through some kind of struggle."
Receiving a Christmas card means a lot to me, even if it contains no more than a signature. I know that everyone is busy these days, and rarely are any of us able to accomplish all that we would like to. So when someone takes the time to address a card to me and drop it in the mail, it sends the message that I am in their thoughts. Until we are able to find the time to spend time catching up with one another, that small message is enough to warm my heart.
I wouldn't dream of insisting on all or nothing.