Postcrossing - Help
Is it free?
The Postcrossing website is absolutely free! You will not receive any postcards if you do not send any; that is what makes the system work. The more postcards you send, the more you will receive. It is simple, but you still have to send postcards to make it work.
Note that you will need to spend money on postage to send the postcards and to buy postcards if you do not have any.