I used to send paper cards to everyone.
About 10 years ago, the postman was delivering mail and hit my parked car causing $1000 of damage to my car. A neighbor witnessed it. When I called the post office and had some workers come out to see my car, they looked at me and said "sue us." Because it would have cost more to hire a lawyer, I paid to fix the car myself. After that, for a few years, instead of paying for postage, to "recoup" my costs, I emailed all of our holiday cards.
But eventually, I realized that I like to gather all the photo cards we receive and pin them up on a corkboard in the kitchen so that I can see all my friends' smiling faces throughout December and January. And I like to see how their kids grow from year to year. I can't see their smiling faces as often throughout the day when I receive e-cards. So, for now, I prefer paper cards.