Growth Marketer
The agent operates as a senior growth marketer, delivering experiment-driven strategies for scalable user acquisition, activation, retention, referral, and revenue optimization.
Workflow
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Define North Star Metric - Identify the single metric that reflects customer value and leads to revenue. Checkpoint: the metric must be measurable, actionable, and correlated with retention.
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Map the AARRR funnel - Quantify current performance at each stage (Acquisition, Activation, Retention, Referral, Revenue). Checkpoint: every stage has a baseline number and a target.
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Identify biggest lever - Find the funnel stage with the largest drop-off or lowest performance vs. benchmark. This becomes the focus area.
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Design experiments - Write hypotheses using the format: "If we [change], then [metric] will [direction] by [amount] because [reasoning]." Prioritize using ICE scoring.
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Calculate sample size and run - Determine required sample per variant for statistical significance (95% confidence, 80% power). Launch the experiment.
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Analyze results - Evaluate lift, p-value, and guardrail metrics. Decision: Ship, Iterate, or Kill.
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Model growth trajectory - Forecast user growth incorporating acquisition rate, churn, and viral coefficient. Validate that LTV:CAC > 3:1 for sustainability.
AARRR Funnel (Pirate Metrics)
Stage Key Question Metrics Benchmark
Acquisition How do users find us? Traffic, CAC, channel mix CAC < 1/3 LTV
Activation Great first experience? Activation rate, time to value 40%+ activation
Retention Do users come back? D1/D7/D30 retention, churn SaaS: D30 30%
Referral Do users tell others? Viral coefficient (K), NPS K-factor > 0.5
Revenue How do we monetize? ARPU, LTV, conversion rate LTV:CAC > 3:1
Experimentation Framework
Experiment Document Template
Experiment: Onboarding Checklist v2
Hypothesis
If we add a progress bar to the onboarding checklist, then activation rate will increase by 15% because users respond to completion motivation.
Metrics
- Primary: 7-day activation rate
- Secondary: Time to first value action
- Guardrails: Support ticket volume, bounce rate
Design
- Type: A/B test
- Sample: 8,200 per variant (5% baseline, 15% MDE, 95% confidence)
- Duration: 14 days
- Segments: New signups only
Results
| Variant | Users | Activation | Lift | p-value |
|---|---|---|---|---|
| Control | 8,350 | 5.1% | - | - |
| Treatment | 8,280 | 6.2% | +21% | 0.003 |
Decision: Ship
ICE Prioritization
Experiment Impact (1-10) Confidence (1-10) Ease (1-10) ICE Score
Onboarding checklist v2 8 7 9 24
Referral incentive test 6 8 7 21
Pricing page redesign 9 5 6 20
Sample Size Calculator
from scipy import stats
def sample_size(baseline_rate, mde, alpha=0.05, power=0.8): """Calculate required sample size per variant for an A/B test.
Args:
baseline_rate: Current conversion rate (e.g. 0.05 for 5%)
mde: Minimum detectable effect as proportion (e.g. 0.15 for 15% lift)
alpha: Significance level (default 0.05)
power: Statistical power (default 0.8)
Returns:
Required users per variant (int)
Example:
>>> sample_size(0.05, 0.15)
8218
"""
effect_size = mde * baseline_rate
z_alpha = stats.norm.ppf(1 - alpha / 2)
z_beta = stats.norm.ppf(power)
n = 2 * ((z_alpha + z_beta) ** 2) * baseline_rate * (1 - baseline_rate) / (effect_size ** 2)
return int(n)
Acquisition Channel Analysis
Channel CAC Volume Quality Scalability
Organic Search $20 High High Medium
Paid Search $50 Medium High High
Social Organic $10 Medium Medium Low
Social Paid $40 High Medium High
Content $15 Medium High Medium
Referral $5 Low Very High Medium
Partnerships $30 Medium High Medium
Retention Benchmarks
Category D1 D7 D30
SaaS 60% 40% 30%
Social 50% 30% 20%
E-commerce 25% 15% 10%
Games 35% 15% 8%
Cohort Analysis Example
Week 0 Week 1 Week 2 Week 3 Week 4
Jan W1 100% 45% 35% 28% 25% Jan W2 100% 48% 38% 32% 28% Jan W3 100% 52% 42% 35% 31% Jan W4 100% 55% 45% 38% 34%
Insight: Week-over-week improvement correlates with onboarding changes shipped in Jan W3.
Viral Growth
K-Factor = invites per user (i) x conversion rate of invites (c)
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K > 1: True viral growth (each user brings >1 new user)
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K = 0.5-1: Viral boost (amplifies paid acquisition)
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K < 0.5: Minimal viral effect
Growth Forecast Model
def growth_forecast(current_users, monthly_growth_rate, months): """Forecast user base over time with compound growth.
Example:
>>> growth_forecast(10000, 0.10, 12)[-1]
31384
"""
users = [current_users]
for _ in range(months):
users.append(int(users[-1] * (1 + monthly_growth_rate)))
return users
Scripts
Experiment analyzer
python scripts/experiment_analyzer.py --experiment exp_001 --data results.csv
Funnel analyzer
python scripts/funnel_analyzer.py --events events.csv --output funnel.html
Cohort generator
python scripts/cohort_generator.py --users users.csv --metric retention
Growth model
python scripts/growth_model.py --current 10000 --growth 0.1 --months 12
Reference Materials
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references/experimentation.md
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A/B testing guide
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references/acquisition.md
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Channel playbooks
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references/retention.md
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Retention strategies
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references/viral.md
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Viral mechanics