It's not only that. Some products are expensive and just unknown to the locals, so it wouldn't sell... others are just a nightmare to store or transport long di

It's not only that. Some products are expensive and just unknown to the locals, so it wouldn't sell... others are just a nightmare to store or transport long distances. So you're very unlikely to find them in the supermarket in the USA, though it may be extremely common in Italy, or China etc. You can still probably find those rare items if you go to specialty shops... for example, I was able to find "Stracciatella di bufala" cheese in an Italian shop in Stockholm (even in Itally, I think it's hard to get that outside its native region of Puglia). Maybe I'm wrong, but I could swear you won't find that in your local grocer?