There are many commercial greetings to choose from when selecting a Christmas card, but a card with a personal message is always more heart-warming for the person receiving it. You probably wouldn't give your mother a card that only said "Merry Christmas, Love Ed," because the greeting would feel cold and impersonal. The same theory can be applied when selecting a business Christmas greeting.
Just because you are sending out a large quantity of cards, does not mean the quality of the message has to suffer. Creating a personalized greeting and/or signature tells your business contacts that you put a lot of thought into your holiday greeting. For example, instead of writing "hope you have a great holiday," or “Merry Christmas and a Happy New Year,” you can write "All of us at (company) wish you and your family a safe and happy holiday." Now instead of being a cliché, your card includes a heart-felt holiday wish that everyone will appreciate.