Two beggars are sitting side by side on a street in Rome.
One has a cross in front of him; the other one the Star of David. Many people go by and look at both beggars, but only put money into the hat of the beggar sitting behind the cross.
A priest comes by, stops and watches throngs of people giving money to the beggar behind the cross, but none give to the beggar behind the Star of David.
Finally, the priest goes over to the beggar behind the Star of David and says, "My poor fellow, don't you understand? This is a Catholic country; this city is the seat of Catholicism. People aren't going to give you money if you sit there with a Star of David in front of you, especially when you're sitting beside a beggar who has a cross. In fact, they would probably give to him just out of spite."
The beggar behind the Star of David listened to the priest, turned to the other beggar with the cross and said: "Moishe, look who's trying to teach the Goldstein brothers about marketing."