referral-program

Overview

Designs referral programs that turn users into your best sales channel. Dropbox grew 3900% with referrals. The best growth is growth that pays for itself.

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1. When to Apply

| Trigger | Behavior | |---------|----------| | Reducing CAC | Referral program design | | "referral", "레퍼럴" | Full program setup guide | | Users already sharing organically | Amplify existing behavior |

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2. Referral Program Types

| Type | Mechanism | Best For | Example | |------|-----------|----------|---------| | Double-sided | Both referrer and referee get reward | SaaS, marketplace | Dropbox, Airbnb | | One-sided (referrer) | Only referrer gets reward | Low-friction products | Cash referral bonus | | One-sided (referee) | Only new user gets benefit | Trial/freemium | "Get 1 month free" | | Tiered | Rewards increase with more referrals | Power users | Ambassador programs | | Milestone | Reward at specific referral counts | Viral products | "Invite 5 → unlock feature" |

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3. Program Design Template

# Referral Program: [Product Name]

## Incentive Structure
| Role | Reward | Trigger |
|------|--------|---------|
| Referrer | [e.g., 1 month free] | When referee [signs up / pays / activates] |
| Referee | [e.g., 20% off first month] | On signup via referral link |

## Sharing Mechanics
- **Unique referral link**: [user].product.com/ref/[code]
- **Share channels**: Copy link, Email, Twitter, WhatsApp
- **In-app placement**: Settings → "Invite Friends" + post-value moment

## Tracking
- Referral code in URL → cookie → attribution on signup
- Dashboard: referrals sent, signed up, converted, rewards earned

## Reward Fulfillment
- Automatic credit/discount application
- Email notification on successful referral
- Leaderboard for top referrers (optional)

## Anti-Fraud Rules
- Max [N] referrals per user per month
- Self-referral detection (same IP, email domain)
- Minimum activity threshold before reward unlock

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4. When to Launch Referrals

Prerequisites (don't launch without these):

• [ ] Product delivers value (NPS > 30)
• [ ] Users are already sharing organically (even a few)
• [ ] Retention is healthy (Week 4 > 20%)
• [ ] Referral can be tracked technically
• [ ] Reward economics work (reward cost < CAC savings)

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5. Viral Coefficient

K = invites per user × conversion rate of invites

K > 1.0 → Viral growth (each user brings >1 new user)
K = 0.5 → Amplified growth (50% boost to other channels)
K = 0.1 → Minimal viral effect (optimize or rethink)

Example:
  Average invites per user: 3
  Invite conversion rate: 20%
  K = 3 × 0.20 = 0.6 (good amplifier)

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6. Tool Coordination

| Tool | Purpose | |------|---------| | Write | Generate program design docs | | Read | Reference product metrics, NPS data |

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7. Boundaries

Will:

• Design referral program incentives and mechanics
• Provide anti-fraud guidelines
• Calculate viral coefficient
• Recommend timing for launch

Will Not:

• Implement referral tracking code
• Process rewards or payments
• Manage referral fraud detection in production
• Guarantee viral growth