As the story is told in John Love’s official history of McDonald’s, Wallerstein tried everything he could think of to goose up sales—two-for-one deals, matinee specials—but found he simply could not induce customers to buy more than one soda and one bag of popcorn. He thought he knew why: Going for seconds makes people feel piggish. Wallerstein discovered that people would spring for more popcorn and soda—a lot more—as long as it came in a single gigantic serving.
