Schmitt, Skiera, Van den Bulte 2011 (JoM) — referred customers ≥16% higher LTV than matched non-referred; retention persists, margin decays

Claim: Schmitt, Skiera, and Van den Bulte (2011), "Referral Programs and Customer Value," tracked ~10,000 customers of a German retail bank for ~33 months and found that referred customers had:

• Higher contribution margins, with the advantage eroding over time
• Higher retention rates, with the advantage persisting
• Higher lifetime value — at least 16% higher than matched non-referred customers
• Substantial variation across segments — private-banking referrals 36% higher value; some retail-bank segments minimal or zero difference

Won the 2011 MSI/H. Paul Root Award.

Source: Schmitt, P., Skiera, B., & Van den Bulte, C. (2011). "Referral Programs and Customer Value." Journal of Marketing 75(1), 46–59.

Confidence: Verified (banking context). Cross-domain mapping to trades is Directional but theory-consistent.

For Candid — uncomfortable translation: A strong-tie referral from a fellow contractor doesn't just convert better at the front end; it produces a longer-retained client because the referring relationship continues to police the engagement. The referrer is exposed to reputation cost if the referred relationship goes poorly — that exposure works on both sides.

Mechanism decomposition: [[van-den-bulte-2018-better-matching-social-enrichment]].