You can cut a medium pizza into as many postage-stamp-sized slices as you want, but that won't make it a large.
Pizzaiolo has some of the best pizza slices in the city, but I am never ordering delivery from them again. The delivery menu says a medium pizza has 8 slices, and a large 10. So we ordered a large for almost $25. Turns out the slices are tiny - barely a few bites. By any normal pizza standard, this is a six-slice pizza. For 25 bucks. I don't think so.
And to boot, the pizza came undercooked. Nowhere on the menu does it say that you have to finish baking it in your own oven.