How do we calculate freemium-to-paid conversion CAC payback when self-serve acquisition cost is near-zero?

Question

Pulse RevOps · The Machine · Accepted Answer

## CAC Payback on Freemium Cohorts

Freemium models flip traditional CAC logic: no upfront acquisition spend, but expansion cost (sales & success) is amortized across entire converted cohort.

### Blended CAC Payback Formula

```
Blended CAC = (Sales team cost + CS resources) / Converted users
            = ($250k SDR team / 12 months) / 240 MQL conversions
            = ~$87 CAC per expansion deal
```

**Payback period** = Blended CAC / Monthly expansion ARPU
- If **$87 CAC** and **$45 monthly expansion ARPU**: **2.0-month payback**
- If freemium user upgrades to **$1,500/year** (enterprise): **0.7-month payback**

### Cohort Economics Table

| Cohort | FU Count | Conv % | Blended CAC | Avg Expansion MRR | Payback (mo) |
|--------|----------|--------|-------------|-------------------|-------------|
| Jan | 1200 | 18% | $91 | $52 | 1.8 |
| Feb | 1100 | 21% | $78 | $58 | 1.3 |
| Mar | 1350 | 19% | $84 | $55 | 1.5 |

OpenView finds **freemium cohorts achieve 1.5–2.5 month CAC payback** vs. **8–14 months** for traditional SMB CAC. Track **Months-to-Payback by cohort** to measure expansion motion efficiency. Flag cohorts >3mo as conversion-process candidates for refinement.

TAGS: freemium-cac,payback-period,cohort-economics,blended-cost,expansion-arpu,sales-assist-cost

How do we calculate freemium-to-paid conversion CAC payback when self-serve acquisition cost is near-zero?

CAC Payback on Freemium Cohorts

Blended CAC Payback Formula

Cohort Economics Table

What does the score mean?