Viral Coefficient
01 Definition
Viral Coefficient meaning: The average number of new users each existing user brings in through sharing or invites.
The viral coefficient measures how many new users each current user generates by inviting or referring others. You multiply the invites per user by the share who convert. A value above 1 means self-sustaining growth, while most real products fall below that.
Also called
Why it matters
How Viral Coefficient fits the work
The viral coefficient turns word-of-mouth growth into a number teams can track, showing whether referrals meaningfully add users without paid acquisition.
In context
If each user sends 4 invites and 25 percent sign up, the viral coefficient is 1.0, meaning each user brings one new user.
Practical note
A coefficient above 1 is rare and hard to sustain. The number also ignores time between invites, so pair it with cycle length to understand real growth speed.