DoorDash is plunking down $8 billion of its stock to buy Finland-based food delivery service Wolt, underscoring the U.S. company’s ambition to become a global operator. But that ambition begs a very real question: Is there any reason to think there are global economies of scale for a business focused on local delivery of restaurant meals and groceries?

This isn’t search or social media, where a company can press a button and make their service available for everyone everywhere. In every country where it operates, DoorDash has to line up couriers, negotiate partnerships with restaurants and grocery chains and arrange marketing. Wolt certainly puts DoorDash into plenty of new markets, although they’re mostly smaller countries in regions like the Baltics, Eastern Europe and Scandinavia. A combined DoorDash-Wolt may be able to strike deals with some pan-European grocery chains (although it faces plenty of competition in doing so). But it’s not obvious that operating in parts of Europe will help DoorDash expand elsewhere in the world or operate more efficiently anywhere.