I am twenty six years old and I mail cards. In a time when everyone has multiple email addresses, a Facebook profile, and a cell phone you can text to, it's easy to use one of these options to send a message. However, there is a far superior alternative you should consider (like you would "consider" filling your tank with gas if you wanted to drive it). It's the greeting card. Going forward, I invite you to join me in trying to show some card respect.
Definition of card respect: If someone mails you cards to recognize occasions in your life, it's polite to reciprocate with this (almost) ancient form of communication.
Of course a phone call, email, text, or Facebook wall post is better than nothing...however, if you exercise a little organizational and planning discipline, an on-time* hand written card will floor the recipient.
How you benefit:
~ Your grandma keeps the card on her mantle for 3 months (old people don't throw things away) and every time she looks at it she thinks of you and her heart is happy.
~ Your mom let's out a few tears of joy like she does after a Hallmark commercial because she's literally in one.
~ You will keep receiving cards from the people who send them (if they stop receiving cards all together, they will eventually stop sending them and we'll have made something else extinct**).
Over the years I've neglected to send a lot of cards. I'll be selfish with my time and then scramble the day of to make a phone call and send flowers or overnight a last minute gift online. I thought I was being a thoughtful daughter, sister, granddaughter, niece, and friend. But the flowers die and a space is made in the closet for the rushed gift. If I had mailed a card that arrived on or before the birthday/holiday that would have been a true present.
So give it a shot. Hand write a thoughtful note on a card to someone you care about and drop it in the mail. Let me know how it goes over.
*Intra-state delivery is usually 2 days or less and inter-state deliver can range from 3 to 7 days.
**If you think you are being green by using e-communication in this context, I'm sorry, but, I have to disagree. It's a greeting card. You're not mailing a Pottery Barn catalog weekly to every home in the United States :)