Cost Per Lead vs. Cost Per Job Won: Why NZ Trades Are Measuring the Wrong Number

Cheap leads. Zero jobs. You're measuring the wrong thing.

If you run a trade or service business in New Zealand, you've probably had this conversation: "Our Facebook ads are killing it — look at all these leads." Then someone looks at the job board and it's half empty. The phone rang. The inbox filled up. But the invoices didn't follow.

That gap — between leads in and jobs won — is where marketing budgets can quietly bleed out. And the reason it keeps happening is simple: operators are optimising for a number that doesn't pay wages.

What 'cost per lead' actually measures

Cost per lead (CPL) is exactly what it sounds like. You divide your total marketing spend by the number of enquiries you received. Spend $1,000, get 50 leads, your CPL is $20. Clean. Simple. Satisfying.

The problem is that CPL only measures the cost of generating interest. It says nothing about what happens after someone fills in your contact form or calls your number. CPL measures the cost of moving someone from complete stranger to interested prospect — nothing more.

Cost per acquired job (sometimes called cost per acquisition, or CPA) is the number that actually matters. It measures the cost of converting that interest into a paid invoice. And it's almost always significantly higher than your CPL — because not every lead becomes a customer.

Here's the relationship in plain terms: if your CPL is $50 and only 10% of your leads turn into booked jobs, your cost per acquired job is $500. That's the number that should be sitting at the top of your monthly report. Most operators never calculate it.

The maths that changes how you see your marketing

Let's run two hypothetical scenarios. These numbers are illustrative of the principle — actual results will vary by trade, region, and channel quality — but they reflect the kind of dynamic you'd see across two different lead channels: say, a low-cost social media lead aggregator versus a higher-intent Google search campaign.

Channel A — the 'cheap' leads:
- Cost per lead: $12
- Leads purchased: 100
- Total spend: $1,200
- Conversion rate (lead to booked job): 8%
- Jobs won: 8
- Cost per acquired job: $150

Channel B — the 'expensive' leads:
- Cost per lead: $45
- Leads purchased: 100
- Total spend: $4,500
- Conversion rate (lead to booked job): 25%
- Jobs won: 25
- Cost per acquired job: $180

These figures are hypothetical. The conversion rates chosen here are for illustration only — real-world rates will depend heavily on trade type, campaign quality, and how quickly you follow up. The key point is not the specific numbers but the method: even a modest difference in conversion rate changes which channel actually delivers work.

Now flip it to a fixed-budget comparison. Say you have $4,500 to spend, using the same hypothetical figures:

• Channel A at $12 CPL: 375 leads, 8% conversion = 30 jobs
• Channel B at $45 CPL: 100 leads, 25% conversion = 25 jobs

At these particular rates, Channel A wins on volume — but at the cost of chasing 345 leads that didn't convert. Adjust the conversion rates and the outcome shifts. That's precisely the point: the right answer depends entirely on your actual conversion data, which most operators don't track.

This is why the core insight holds regardless of the specific numbers: a lead that's pricier up front can deliver a lower final acquisition cost if it converts at a meaningfully higher rate. The gap between lead cost and lead quality is the core issue for any service-based business.

Why conversion rates vary so much between channels

This isn't random. Leads from different sources arrive with very different levels of intent, and intent drives conversion.

Someone who searches "emergency plumber Christchurch" on Google and clicks your ad is in problem-solving mode right now. They need a plumber. They're not browsing. Intent-driven search leads for trade services often convert at higher rates than passive social audiences — though execution quality matters for both channels, and a well-run social campaign can outperform a poorly-managed search campaign.

By contrast, a lead that comes from a low-cost aggregator platform — where your details sit alongside several competitors, or where someone submitted a form without strong purchase intent — is typically comparison-shopping at best, or not actually ready to buy at worst. You might get 100 of those enquiries for $1,200. But if the majority don't book, you've spent $1,200 generating a handful of jobs and wasted the time it took to chase the rest.

Time isn't free. Every quote you send that goes nowhere, every callback that gets ignored, every site visit for a job that gets awarded to someone else — that's real overhead that doesn't show up in your CPL figure but absolutely shows up in your cost per acquired job.

The vanity metric problem

Here's where it gets uncomfortable. Most trade operators don't actually connect their enquiry source to their invoices.

A lead comes in. It gets written in a notebook, or entered into a WhatsApp thread, or logged in a spreadsheet without the source attached. If it turns into a job, great. If it doesn't, it disappears. Nowhere in that process does anyone ask: which channel did this lead come from, and did it actually pay us?

Without that connection — enquiry source to paid invoice — you're optimising for a vanity metric. You're celebrating your low CPL while your cost per acquired job climbs silently. You might cut the channel that actually produces work because it "looks expensive" on paper, and double down on the cheap-lead channel that's generating noise but not revenue.

This is a pattern observed in trade marketing. Operators track what's easy to count (enquiries) rather than what actually matters (jobs invoiced, by source). The result is that budget flows toward the channel that makes the marketing report look good, not the channel that fills the job board.

A practical three-column tracker to start with

You don't need sophisticated software to fix this. You need a habit and three columns in a spreadsheet:

1. Enquiry source — where did this lead come from? (Google Ads, Facebook, referral, Google Business Profile, job board, etc.)
2. Outcome — did it become a booked job, a quote sent but not won, or no response?
3. Invoice value — if it booked, what did you invoice?

Review that sheet monthly. After 60 to 90 days, you'll start seeing something real: which channel is actually producing paid work, and at what cost. Not leads. Work.

Once you have that data, calculate your cost per acquired job per channel. Take your total spend on that channel and divide it by the number of jobs it produced. That's your real number. That's what you use to make decisions.

What good looks like across NZ trades

Reliable, NZ-specific benchmark data for lead-to-job conversion rates by trade is not publicly established, and figures vary enormously by region, channel, business size, and how quickly leads are followed up. What follows are indicative ranges based on general industry observation — not verified benchmarks — and should be treated as a starting point for comparison against your own numbers, not as targets.

Plumbing tends to see relatively strong conversion rates compared to other trades, in part because many plumbing enquiries are emergency-driven rather than comparison-shopping situations. HVAC and heat pump work can be more seasonal and quote-intensive, which typically weighs on conversion. Painting and general contracting often involve longer quote cycles and multiple competing bids, which can compress close rates — though follow-up discipline makes a significant difference.

Roofing is a useful example of why job value matters as much as lead cost. A higher CPL can still make sense if it produces a large-value job, because the cost per acquired job remains proportionate to the revenue. Conversely, cheap roofing leads from aggregator sites with low conversion rates can make even a modest CPL look poor once you do the real maths. The principle applies regardless of trade: what matters is not the cost to fill your inbox, but the cost to put a job on the board relative to what that job is worth.

What to actually do this week

Start tagging your enquiries by source, today. It doesn't have to be perfect. Even a rough split — Google vs. social vs. referral vs. other — gives you something to work with after 60 days.

If you're running paid ads and your agency is sending you a CPL report without a corresponding conversion-to-job rate, ask for it. If they can't produce it, that's worth understanding why.

And if you're choosing between two channels based on lead cost alone, run the scenario above with your own numbers. Plug in your real conversion rates. The answer often surprises people.

In many cases, the cheapest lead is not the most valuable one — but the only way to know for certain is to track conversion by source. The most valuable lead is the one that turns into a job, and the channel that consistently delivers those leads is the one worth funding.

Save this. Show it to whoever runs your ads.