Cards are just one way to keep in touch as well as to express emotions such as love, congratulations, condolences and gratitude. Although we live in a world run by digital communication, a card sent through postal mail can mean a lot to both the sender and the recipient. They can even mean more than an email, an e-card or even a phone call sometimes.
Everybody has a different reason for sending cards. Perhaps it's someone's birthday. Maybe you want someone to know how much you love and appreciate them but are too shy to tell them face-to-face. Maybe you know that receiving snail mail with something as simple as a "hello" will brighten a friend's day. Or maybe there's a young child that would feel like the king of the world if they received an envelope addressed specifically to them in the mailbox one day.