Well, of course you can always send a free e-card. But you get what you pay for most times. The printed card is a memento, like an old photograph or an old polaroid, like that old letter or postcard you've saved for all these years. You can write on it with a Bic pen, and the receiptient will see YOUR words, not some computer generated typeface. And, even better, a printed card lasts, and will be around hundreds of years from now, with proper care. Go ahead, try that with an internet link, or a disk drive.
The printed card is something you can hold. You can frame it and put it on your wall. You can put it in a scrapbook, or in a holder to sit upon your desk. We're sold on the printed card, and think you should be as well. Send one today to a loved one or friend. Or find one to send to your worst enemy and piss them off, heh heh.
Seen against the human lifespan, a printed card is virtually forever.