Product Led Growth

Product-Led Growth (PLG)

Implementing product-led growth strategies — from freemium and free trial models through viral loops, self-serve conversion, and product-qualified leads (PQLs).

When to Use

• Building a product that sells itself (self-serve motion)
• Implementing freemium, free trial, or usage-based models
• Designing viral loops and user-invite mechanics
• Identifying and acting on product-qualified leads
• Driving expansion through in-product upgrades

PLG Metrics

PLG_METRICS = {
    'pql_rate': '% of users meeting PQL criteria each month',
    'activation_rate': '% of signups reaching activation milestone',
    'time_to_value': 'Days from signup to first value moment',
    'self_serve_conversion': '% of users who upgrade without sales touch',
    'viral_coefficient': 'Avg invites sent × invite conversion rate',
    'expansion_revenue': 'Revenue from upgrades within customer base',
}

def identify_pqls(user_behavior: Dict) -> bool:
    """Determine if a user qualifies as a Product-Qualified Lead."""
    criteria = 0
    if user_behavior.get('feature_adoption', 0) >= 5: criteria += 1
    if user_behavior.get('team_members', 0) >= 3: criteria += 1
    if user_behavior.get('usage_frequency', 0) >= 10: criteria += 1
    if user_behavior.get('support_tickets', 0) <= 2: criteria += 1
    return criteria >= 3

Common Pitfalls

1. Free tier too generous — users never need to pay; limit high-value features
2. No activation focus — signups that never activate are wasted; optimize first value
3. Sales interference — sales contacting free users too early kills PLG motion
4. No PQL scoring — don't know which free users are sales-ready; build PQL model
5. Viral loop friction — invite flows that are too complex kill virality

Verification Checklist

• Activation milestone defined (the "aha moment")
• Free → paid conversion path clear and tested
• PQL scoring model built and validated
• Self-serve upgrade flow (no sales required)
• Viral/invite loop implemented
• Expansion triggers identified (usage limits, team invites)
• PLG + sales-led hybrid model defined (if applicable)