Initially you can send 5 postcards. As you exchange more postcards with other members of the site, the number of postcards that you can send (that is, have simultaneously traveling) will increase. This system encourages new users to try out the project while allowing more avid members to send more postcards.

For every 20 postcards that you send and have been registered, the number of postcards that you can send will increment by 1. When you reach 100 postcards registered, you will be allowed 1 extra postcard for every 50 postcards sent and registered.

• If you have sent between 0 and 19 postcards, you can send 5 postcards.
• If you have sent between 20 and 39 postcards, you can send 6 postcards.
• If you have sent between 40 and 59 postcards, you can send 7 postcards.
• If you have sent between 60 and 79 postcards, you can send 8 postcards.
• If you have sent between 80 and 99 postcards, you can send 9 postcards.
• If you have sent between 100 and 149 postcards, you can send 10 postcards.
• If you have sent between 150 and 199 postcards, you can send 11 postcards.
• If you have sent between 200 and 249 postcards, you can send 12 postcards.
• ... and so on, in increments of 1 postcard for each 50 you send.

This means that if you have sent 21 postcards, you can have at most 6 postcards traveling simultaneously to other members.

Once you have reached your limit, the only way to free up a slot to send another postcard is to either have a postcard you have sent be registered or have a postcard you have sent time out (expire) in transit. Postcards expire after traveling 60 days although they can still be (and often are) registered after that time frame.

Note: Adjustments to these limits may occur in the future.