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 an address. This address will be accompanied by an ID (a unique code that identifies your postcard).
3. Choose a postcard, write something nice on it along with the assigned ID and mail it to the address you were previously 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!

For more details, please check the About section - If you still have questions, give us a shout!