When Americans are too busy or lazy to cook, they often place an order with their favorite Chinese restaurant. So who do people in China call when they want food delivered? Increasingly, McDonald's and KFC.

Delivery is becoming an important part of the growth strategy at McDonald's Corp. and Yum Brands Inc.'s KFC chain in parts of the world where cities are too crowded and real estate costs too high to justify building drive-throughs.

...