Cost per lead is a lovely metric. It’s simple, it updates in real time and it fits neatly in a dashboard. It’s also the easiest number in marketing to improve while making the business worse.
Cut the qualifying questions and CPL drops. Widen the targeting to people who’ll never buy and CPL drops. Neither change helps anyone except the person writing the weekly report.
So what should you watch instead? Not instead, exactly. Alongside.
Contact rate
What share of leads can your team actually reach? It’s the first sign of trouble with lead quality and it shows up within days, long before anything closes.
A falling contact rate usually means one of three things: fake or mistyped details, people who didn’t realise they’d asked to be called, or a sales team that’s taking too long to call. The first two are a media problem. The third isn’t, and it’s worth checking before anyone changes the campaign.
Qualification rate
Of the leads you reach, how many meet the criteria your sales team cares about? This is where a clear lead definition pays for itself, because everyone is counting the same thing.
Track it by channel, campaign and, if you can, by creative. You’ll often find one ad producing cheap leads that rarely qualify and another producing expensive ones that nearly always do.
Cost per qualified lead
This is the number we’d put at the top of the dashboard if we could only have one. Divide spend by qualified leads instead of all leads.
A quick example. Campaign A delivers leads at £20 and a third of them qualify. Campaign B delivers leads at £32 and two thirds qualify. On CPL, A wins easily. On cost per qualified lead, A costs £60 and B costs £48. B is the better campaign by a clear margin, and a CPL-only report would have told you to switch it off.
Speed to first contact
It isn’t strictly a lead quality metric, but it affects every other number on this list. Leads lose interest quickly, especially leads from instant forms. A lead called within ten minutes is a very different prospect from the same lead called the next day.
Measure the time between a lead arriving and the first call attempt. If it’s measured in hours, fixing that may do more for your results than any campaign change.
Pipeline and revenue per lead
Further down the funnel, the numbers get slower but more honest. How many leads become opportunities? What’s the average value of those opportunities? How many close?
These take weeks or months to settle, so they’re no use for daily optimisation. They’re essential for the bigger decisions: which channels deserve more budget, which offers to keep and what a lead is really worth to you.
Send the outcomes back to the platforms
This is the step most teams skip. Meta, TikTok and most DSPs can receive data about what happened to a lead after it was delivered. If you tell them which leads qualified or bought, their delivery systems start looking for more people like those, instead of more people who simply fill in forms.
It takes some setup with your CRM and the Conversions API or Events API. It’s also one of the most effective things you can do for lead quality, because you’re teaching the algorithm what good looks like rather than hoping it guesses.
A weekly view that fits on one screen
For most lead programmes, we’d suggest five numbers, broken down by channel:
- Leads delivered and cost per lead
- Contact rate
- Qualification rate
- Cost per qualified lead
- Median time to first contact
Add pipeline and revenue monthly, once the data has had time to mature. That’s the reporting we build into every CPL programme, reconciled against the client’s own CRM rather than ours.
It’s less exciting than a dashboard full of charts. It’s also much harder to fool.