Like ShaisMom I would send a card to everyone in the United States and Canada, but I would not send them overseas because of the cost and I would not expect them to send one to me for the same reason. I think it's only fair if you sign up on the card list that you send cards to all, if not just do not go on the list and ask the people for their address and you can send them to whoever you want to send them to with no obligation. The same with the e.mail list.
It was a lot of fun last year and there weren't that many people and it was very simple, if you are on the list you send them, if you are not you send them to who you want to send them too.
Jackie