Just came across this snippet which may also be thought provoking:
"Antica Pizzeria da Michele, one of the city's oldest, has been family-run for generations; the current padroni -- Don Antonio and Don Luigi Condurro -- were delivered here, by a midwife, perhaps on a pizzamaker's paddle. People call them "Don" in sign of respect. The two "Dons" make only two kinds of pizza. One, la margherita, has tomato sauce, fior di latte cow's milk mozzarella and basil. The other has neither cheese nor basil. You're lucky if you get a salted anchovy. "
"Simplicity," said Don Antonio as he kneaded his dough. "We like them simple. You want other toppings, you have to bring them yourself."
I asked about the cow's milk fior di latte -- Americans seem to prefer mozzarella di bufala. "Buffalo-milk mozzarella is too fatty, too heavy, too wet -- it ruins a pizza."