Cost advantages from producing multiple products on shared assets — distribution, data, identity, sales force, brand. Neumann lists it under returns to scale; Porter treats shared activities as a source of interrelationships between business units.
How Scope economies work
A multi-product firm's marginal product costs less to build and sell than a single-product competitor's, and the bundle raises switching costs. Fails when the shared asset is not actually shared (different buyer, different data model).
How companies won with Scope economies
From the win chains in Strategy Canon case studies: what the winner did, and what its rival did at the same step.
vs. BigCommerce
Shopify
Scope economies in payments
What it did
Payments inside the store (2013); outside gateways cost more (2015)
BigCommerce
Declined its own processor to stay neutral; 74% of 2019 revenue was subscriptions vs Shopify's 59% merchant solutions