Why Shake Shack uses the classic Martin's potato rolls for their buns

Any burger not made on these Martin's Potato Rolls just doesn't stand up. Shake Shack is one of my favorite classic American burgers and it's nice to know that they went with another classic American company for their bread. For all the talk of ingredients, I think the true secret on why Shake Shack tastes so good is because of these Martin's potato rolls.