Here's my point:
Ali, Bleu and Fisher take their card to a incredible level. They set the standard, but whether you follow in their footsteps or not, isn't important. What is important is the opportunity you have to utilize a holiday card, and your stationery to remind people what you do for a living.
No photographer should ever send out a store-bought card EVER! That includes not only the holidays, but your thank-you notes and other stationery. USE YOUR IMAGES! And, on the back of the card at the bottom, just like Hallmark, give people a little more information with your website, email address and phone number.
Sharing your work in a holiday card is a perfect way to advertise. It's the perfect way to thank people for their support during the year, wish them happy holidays and remind them you're an artist!