Definition
Invite Conversion Rate measures the effectiveness of your referral mechanism by tracking what proportion of invited users actually complete registration. This metric is the "c" component in the viral coefficient formula (K = i × c) and is often more actionable than the K-factor itself — improving invite conversion through better landing pages, incentives, or social proof directly amplifies viral growth without requiring users to send more invites.
Formula
How to measure
Track `invite_sent` and `referred_signup` events. Calculate signups from invites ÷ total invites sent. Segment by invite channel (email, SMS, link share, social), relationship between inviter/invitee, and incentive type to identify the highest-converting paths.
Industry benchmarks
Email invites: 5–15% conversion. Social/messaging invites: 10–25%. Direct link shares: 3–8%. Incentivized referrals (both parties rewarded): 15–30%. Non-incentivized: 5–10%.