What a lead really costs

Every advertising platform will tell you your cost per lead. Google Ads reports it, Meta reports it, and most agencies put it at the top of the monthly report. It is a useful number. It is also the number that most often leads businesses to spend money in the wrong place.

The problem is simple: a lead is not a sale. Two campaigns can produce leads at the same cost and deliver completely different results once those leads reach the business.

The three numbers that matter

When I review an account, I want three numbers side by side for every campaign:

1. Cost per lead. What the platform reports. Total spend divided by enquiries.
2. Lead to sale rate. Of the enquiries that campaign produced, how many became paying work.
3. Cost per sale. Spend divided by the sales that campaign actually produced.

The third number is the one that tells you whether to spend more. The first number on its own can point you the wrong way.

How cheap leads become expensive

A common pattern: a broad keyword or a loose audience produces a flood of low-cost enquiries. The cost per lead looks excellent. But the enquiries are small jobs, price shoppers or people outside the service area, and the team spends hours quoting work that never closes.

Meanwhile a tighter campaign with a higher cost per lead produces enquiries that close at a much better rate. On a cost per sale basis, the “expensive” campaign is the cheaper one.

I saw this on a flooring account I worked on at The Agency Alternative, Northern Rivers Flooring. The answer was to deliberately reduce lead volume by tightening targeting and adding qualifying questions to the form. Fewer enquiries came in, but they were the right size and budget, and profit per job went up.

What you need to track it

You do not need an expensive system to measure this. You need three things:

• Every enquiry tagged with its source. Form submissions carry the campaign they came from. Phone calls use a tracking number per channel, so you know which calls came from Google and which came from Meta.
• A simple record of what happened next. Quoted, won, lost. A spreadsheet works if it is kept up to date.
• A monthly join. Match the won jobs back to their source and divide spend by sales per channel.

The discipline is in the second step. Most businesses have the source data. Very few record the outcome against it.

What changes when you measure this way

Budget decisions get easier. Instead of asking “which campaign is cheapest”, you ask “which campaign produces work at a cost we are happy with”, and you move money towards it.

It also changes the conversation with whoever runs your advertising. Clicks and impressions stop being the headline, and the report starts with the number the business owner actually cares about.

If you are not sure what your cost per sale is by channel, that is usually the first thing worth fixing. Get in touch if you would like a second opinion on how yours is set up.