Direct Network Effect
Each new user directly increases value for all existing users. Classic in collaboration, communication, and professional networks.
Test: Does adding one user benefit every existing user immediately?
Two-Sided Network Effect
More sellers attract more buyers; more buyers attract more sellers. Value is a function of cross-side density, not absolute count.
Test: Does each side grow because the other side grew?
Community & Ecosystem Effect
Templates, plugins, shared assets, and collaborative resources make the product more valuable for future users. Requires the same core test.
Test: Does the ecosystem materially improve value for existing users?
Scale, Virality, Data & Integrations
More customers funding R&D, invite loops, data flywheels, and partner ecosystems are distinct structural mechanisms — valuable, but not network effects.
These moats require different growth strategies