There've been plenty of successful physical coins, successful in the sense that they were popular. They certainly don't seem to be a good way to make money for the person actually making them and a whole world of ball ache seems to come along with it.

There was a user here named Gravitate who made the Microsoul coins. He went a bit batty after the constant sniping from users and failures on his part. After doing it for several years I seem to remember him saying his profit was about $5000 in total.