This serves as a PSA on behalf of holiday card-receiving Jews everywhere.
Every year I have at least one friend who buys a big box of Christmas cards. Not "Happy Holiday" cards but ones that specifically say "Merry Christmas" on there. Instead of sending me a Hannukah or a generic "Happy Holidays" card, I receive a Merry Christmas card with the words "Merry Christmas" crossed out and "Happy Hannukah" written over them in pen.
Please, please, please for the love of all things that are holy, do not do this. It is so tacky and just shows that you couldn't take out the time to buy just one extra card for a friend. This year I have vowed that if anyone sends me a Merry Christmas card for Hannukah, I will return the favor by sending them a Happy Hannukah card for Christmas. (What? You mean you don't light a Menorah for Christmas?)