Glossary · Digital Economics

Network Effects

also: network effect · direct network effects · indirect network effects

Definition

A network effect exists when the value of a product to each user increases with the number of other users. Direct network effects (messaging apps) work within a single user side; indirect or cross-side network effects (marketplaces) operate across distinct user groups. Strong network effects create winner-take-most markets.

Metcalfe, Reed, and Sarnoff proposed competing scaling laws for network value, but the critical distinction is structure: direct network effects (each user benefits from more users in the same side — e.g. Facebook, WhatsApp), cross-side or indirect network effects (two-sided markets where buyers value more sellers and vice versa — e.g. Uber, OpenTable), and data network effects (each user's behavior improves the product for every other user — e.g. Google Search). The latter have grown dominant in AI/ML-driven businesses.

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Authoritative references