I heard an interesting story about why so many pizza parlors are called "House of Pizza". Apparently there was a greek immigrant who set-up a pizza shop and then realized that there was a great business in it but the challenge was that the capital investment in a pizza oven was very high. So he established a business helping new immigrants set-up their pizza shops by helping them to finance the pizza oven and became the main distributor for pizza ovens in the US. In his efforts to help them establish their pizza parlors he helped them to create their brand and name and had all of the parlors that he helped to set-up become named "X's House of Pizza".