How do you measure the virality of a product?

The virality of a product is measured by the Viral Coefficient, which indicates how many new users are attracted by one existing user.

Formula:

Viral Coefficient = Number of invitations per user × Conversion rate of invitations to new users

If the coefficient is greater than 1, the product grows virally.

Example: if each user invites an average of 3 people, and 20% of them become users, then the coefficient = 3 × 0.2 = 0.6 — there is viral growth, but it is not enough for exponential growth.

Metrics also used for assessment include:

• Time until invitation
• Activity of invited users
• Retention of new users

These data help optimize invitation mechanisms and improve virality.