Amber Grid: Paid Growth Is Getting Expensive
Product Management
hard45 min0 submissionsGoogle
Scenario
Amber Grid's utilities product has grown almost entirely through paid acquisition. That is becoming unsustainable.
Unit economics (monthly):
- Blended CAC: $1,553
- ARPU: $902
- Gross margin: 62%
- Monthly churn: 6.7%
Existing referral behaviour:
- 13% of active users invite at least one other person
- 14% of those invitations convert to a signup
CAC has risen 65% over 18 months as auction competition increased. The CEO wants a growth model that does not depend on buying every user.
Supporting data
trend
- cac increase 18m pct
- 65
referral
- implied k factor
- 0.018
- users inviting pct
- 13
- invite conversion pct
- 14
unit economics
- blended cac
- 1553
- arpu monthly
- 902
- estimated ltv
- 8347
- ltv cac ratio
- 5.37
- gross margin pct
- 62
- monthly churn pct
- 6.7
Your task
Design the growth strategy. Provide:
- Analysis — current unit economics, payback period, and the strength of the existing loop.
- Risks — of the loop you propose and of continuing as-is.
- Recommendation — the specific loop to build and how you would prove it works.
Ready to move forward? Up next: Market Sizing Sprint: India ConsumerNext question
How you'll be graded
100 points, 60% to pass.
- loop design25
- growth model25
- recommendation25
- quantitative reasoning25
Hint
Reveal suggested structure
- LTV = ARPU × gross margin ÷ churn.
- LTV:CAC and payback period = CAC ÷ (ARPU × margin).
- K-factor = invite rate × conversion rate. K ≥ 1 is self-sustaining; below that the loop amplifies but does not replace paid.
- Identify the loop type — viral, content, or paid-recycled.
- Find the weakest step and fix that, rather than adding a new channel.