Wait! :-) There are several things that can make a postcard take a long time to be registered. Here are a few:

• slow postal services
• the member is on holiday or temporarily away
• the member does not have a home Internet connection
• the member did not understand your handwriting and is trying to figure out the ID
• the member is not able to check (or does not receive) their mail daily

Traveling time depends on the postal system of the respective countries so while some postcards may arrive in 5 days, it is as common that postcards take over 30 days to arrive. If it has been well over 30 days, we advise you to contact the recipient of your postcard through private message and ask whether the postcard has arrived (the ID might be blurred, illegible, etc.). After 60 days, the postcard will be set to Expired status and you will be able to request another address.

Be patient, experienced Postcrossers will quickly advise you to do the same - it works!