Tags: commerce analytics concept
Lead Funnel Stages
Date: 2026-09-27
Where the conversion is a form fill, the website’s job ends at the start of a sales process with four or five more stages. Cost per lead is the number marketing reports; cost per customer is the one the business pays, and the stage rates in between can make them differ by fifty times.
Lead funnel stages are the named steps a lead passes through from first enquiry to closed sale, each with an agreed definition, so that marketing and sales can count the same thing.
The stages
| Stage | Definition — usually | Who decides |
|---|---|---|
| Lead | Anyone who submitted contact details | The form |
| MQL — marketing-qualified lead | Meets fit and interest criteria: right industry, size, role; engaged enough | A scoring rule — Lead Quality vs Volume |
| SQL — sales-qualified lead | Sales has spoken to them and confirmed a real need and budget | A salesperson |
| Opportunity | A deal with a value and an expected close date is open | Sales, in the CRM (customer relationship management system) |
| Won | Signed or paid | The contract |
Labels vary. Some organisations add SAL (sales-accepted lead) between MQL and SQL — sales agreeing a lead is worth calling, before calling. Some replace MQL with a PQL — Product-Qualified Leads. What matters is that every stage has a written definition both teams use.
Cost per lead to cost per customer
Worked example. £40 cost per lead (CPL), 1,000 leads.
STAGE RATE FROM PREVIOUS COUNT COST PER UNIT AT THIS STAGE
Lead – 1,000 £40,000 ÷ 1,000 = £40
MQL 40% 400 £40,000 ÷ 400 = £100
SQL 30% 120 £40,000 ÷ 120 = £333
Opportunity 50% 60 £40,000 ÷ 60 = £667
Won 25% 15 £40,000 ÷ 15 = £2,667
Lead-to-customer rate: 0.40 × 0.30 × 0.50 × 0.25 = 1.5%. Customer acquisition cost is £40 ÷ 0.015 = £2,667 — 67 times the headline CPL.
The number to hold: a CPL is meaningless on its own. A £40 lead and a £120 lead can’t be compared until the stage rates are known — Customer Acquisition Cost.
Why the stages exist
- To give marketing a target it can see. Deals close months after the click. MQL or SQL is the earliest stage that still predicts revenue
- To fix the handoff. Most lead leakage is between stages: MQLs no one called, SQLs never logged as opportunities
- To make the conversion rate per stage visible, which is where diagnosis starts — the stage with the collapse is where the problem is
Failure modes
- Optimising to the first stage. Ad platforms bid on whatever conversion they’re told about. Tell them “form submitted” and they’ll find form-fillers — Offline Conversion Imports fixes this by reporting later stages back
- Stage definitions drifting. Sales tightens the SQL bar quietly and the marketing funnel appears to collapse. Date every definition change — Annotation and Change Logs
- Counting leads twice. One person submitting two forms is two leads and one prospect. Deduplicate on email before stage counts — Double Counting
- Reading stage rates too early. A cohort’s win rate isn’t known until its deals have had time to close. Compare cohorts at the same age, not this month’s leads against last year’s — Cohort Analysis