Exactly right. Anyone who has eaten at McD's more than once or twice will hold a mental conception of "McDonald's" which is separate from their mental conception of "hamburger". Partly this arises from the immaculate branding but mostly from the peculiar oneness of the product. That's the genius of the Big Mac. Or should I say, the Big Crack.
A co-worker of mine just coined this moments ago. We were talking about McDonald's food, and how it isn't what you think of when you think, "I want a burger," but that it has its own flavor, like a casserole that only your favorite aunt can make the right way.
"And," I added, "only they have the dangerous chemicals they put in their food to make it so addictive."
"Yes," he said. "Would you like some delicious food crack?"