Module 1: Lead Generation Economics & Commercial Targets
Lesson 2 · Lead Generation Economics & Commercial Targets
Lesson 2 objective
Calculate an economically justified allowable CPL by working backwards from customer contribution and lead-to-customer conversion.
A £40 lead is not inherently cheap. A £200 lead is not inherently expensive.
The correct question is:
How much can this business rationally afford to pay for a lead given the probability that it becomes a profitable customer?
Allowable CPL = Target CAC × Lead-to-Customer Conversion Rate
1. Start with customer economics
Suppose a new customer creates £2,000 of contribution before media.
The business wants to retain £1,200 after acquisition.
That means it can spend up to:
£2,000 − £1,200 = £800 target CAC.
If 10% of leads become customers:
£800 × 10% = £80 allowable CPL.
That £80 target is derived from economics. It is not copied from an industry benchmark.
2. Break-even CPL and target CPL are different
Break-even CPL
The theoretical maximum lead cost before acquisition contribution falls to zero.
Target CPL
The lead cost that preserves the desired contribution or profitability after media.
Operating permanently at break-even may increase revenue while creating little or no economic value.
3. Work through the funnel
Sometimes you know the raw lead-to-customer rate directly.
Sometimes you need to derive it.
Imagine:
| Stage | Rate |
|---|---|
| Lead → qualified lead | 40% |
| Qualified lead → opportunity | 50% |
| Opportunity → customer | 25% |
The combined lead-to-customer rate is:
40% × 50% × 25% = 5%
If target CAC is £1,000:
£1,000 × 5% = £50 allowable raw CPL.
4. Why close-rate improvements change media economics
Assume target CAC remains £1,000.
At a 5% lead-to-customer rate, allowable CPL is £50.
If better qualification and sales follow-up increase lead-to-customer conversion to 8%:
£1,000 × 8% = £80 allowable CPL.
The media team can now pay 60% more per lead without worsening customer acquisition economics.
This is why lead generation is not purely a media problem.
5. Reverse-engineer the entire model
| Input | Example |
|---|---|
| Contribution before media | £2,000 |
| Required contribution after media | £1,200 |
| Target CAC | £800 |
| Lead-to-customer rate | 10% |
| Allowable CPL | £80 |
6. Build ranges, not false precision
Lead-to-customer conversion is rarely fixed.
Instead of assuming exactly 10%, model plausible ranges.
| Lead-to-customer rate | Target CAC | Allowable CPL |
|---|---|---|
| 6% | £800 | £48 |
| 8% | £800 | £64 |
| 10% | £800 | £80 |
| 12% | £800 | £96 |
This tells you how sensitive paid media economics are to sales performance.
7. Calculate your allowable CPL
Allowable CPL calculator
8. Do not inherit somebody else's CPL target
A competitor's £60 CPL tells you almost nothing about what your business can afford.
Differences in margin, close rate, qualification, repeat revenue and operational cost can make the same £60 lead excellent for one business and disastrous for another.
Practical challenge
Calculate three CPL thresholds for your business:
Break-even CPL · Target CPL · Stretch CPL
Then document the lead-to-customer rate assumed behind each number.
Knowledge check
1. Target CAC is £900 and 8% of raw leads become customers. What is the allowable CPL?
2. What happens to allowable CPL if target CAC stays constant but lead-to-customer conversion improves?
3. Why is an industry-average CPL a weak primary target?
4. Contribution before media is £1,500 and the business requires £900 contribution after acquisition. What is target CAC?
Key takeaway
Your allowable CPL should be derived from target customer acquisition economics and the probability that a lead becomes a customer. The better your downstream conversion, the more you can rationally afford to compete for the right lead.