A circus owner walks into a bar to see everyone 
crowded about a table watching a little show. On
the table was an upside down pot and a duck tap
dancing on it. The circus owner was so impressed
that he offered to buy the duck from its owner. 
After some wheelin' and dealin' they settled for
$10000 for the duck and the pot. 

Three days later the circus owner runs back to 
the bar in anger, "Your duck is a ripoff! I put
him on the pot before a whole audience and he 
didn't dance a single step!" 

"So?" asked the ducks former owner, "did you 
remember to light the candle under the pot?"