One lead cost €30. The next €150. Same campaign. Every instinct tells you: scale the €30 leads, kill the expensive ones. Do that, and you'll save money but maybe lose your best customers.
The price says nothing about the value.
Cost per lead (CPR) is the most easily misunderstood metric in B2B marketing. It's precisely measurable, appears objective, and precisely for that reason is so often optimized incorrectly. A cheap lead might be a curious person who wanted a PDF. A expensive lead might be someone with decision-making authority who ultimately signs a contract.
Optimizing solely for CPL systematically enlarges low-cost inquiries and shrinks paying ones. The result is a flawless report but a shrinking pipeline.
What you should measure instead
It's not the cheapest lead that wins, but the one who buys.
Instead of pure CPL, you need a metric that extends all the way to the sale: Cost per SQL, meaning a qualified lead that sales actually accepts, or ideally, Cost per Deal. This assumes that marketing and sales share the same definition of "qualified" and that leads are accurately reported back to the CRM. Otherwise, you'll continue optimizing for the wrong metric, just under a different name.
How I implement this in campaigns
In practice, this means: don't blindly shift bidding strategies to the cheapest lead source, but first examine which audiences, ads, and keywords actually lead to appointments and deals. This takes longer than a CPL dashboard, but provides a more honest picture. Sometimes this means deliberately scaling a more expensive audience because it's the only one that actually makes a purchase.
Frequently Asked Questions
Is a low CPL generally bad?
No, but that's only half the story. A low CPL with a stable or increasing deal rate is a good sign. A low CPL with a decreasing deal rate is a warning sign.
How long does it take for Cost per SQL to become reliable?
That depends on the sales cycle. For short B2B cycles, eight to twelve weeks of data are often sufficient; for longer cycles, you need correspondingly more time and clean CRM tracking from the start.
What if our CRM isn't clean enough for this analysis?
Setting up tracking is the first step, not a nice-to-have for later. Without feedback from the CRM, every campaign inevitably optimizes for CPL, because it's the only available metric.
Should we simply ignore expensive leads?
On the contrary, you should carefully examine where they come from. Often, it is precisely those target groups or channels that actually deserve more budget, not less.
Related: What you're really buying when you hire an agency.
Cost per SQL instead of Cost per Lead is one of the first points I clarify with new clients in the tracking review. More information can be found in our free whitepaper on B2B lead generation, or directly speak without obligation.