It goes like this:

1. You register yourself on the website. You will need to provide your postal address so that you can receive postcards.
2. You request to send a postcard. An address is displayed along with the member's profile. This address will be accompanied by a Postcard ID - a unique code that identifies your postcard.
3. Choose a postcard, write something nice on it along with the assigned Postcard ID, and mail it to the address you were given.
4. Wait, wait, wait. :-)
5. Hoorray! The card arrives to its destination and is registered by the user! Now you too will receive a postcard!