Before You Add a Marketing Hire, Calculate Customer Acquisition Cost

Before you add a marketing hire, calculate customer acquisition cost by dividing the full cost of winning new customers by the number won over a matched period or cohort. That gives you a baseline for judging whether another salary addresses the constraint on growth and whether extra business can support its cost.

A vacancy can be justified even when acquisition is expensive, particularly if the business needs someone to own commercial decisions or manage recurring work.

But the calculation should come before the job description, so you can distinguish a capacity problem from weak conversion, missing measurement or an offer that attracts unsuitable enquiries.

What belongs in the acquisition budget?

The Corporate Finance Institute definition divides acquisition costs by the number of new customers acquired.

For a founder-led services business, the numerator needs to include the sales work required to turn an enquiry into a paying client.

Advertising spend alone leaves out the people handling campaigns, qualifying enquiries and preparing proposals.

Include the acquisition share of employee costs, agency fees, campaign expenditure and relevant software, along with sales time spent winning new business.

Allocate shared costs consistently, recording how you divided a marketer's time between acquisition and existing-customer work, for example.

If the founder handles sales without drawing a corresponding salary, record those hours separately and use a stated replacement-cost assumption when assessing the economics of transferring that work to an employee.

Exclude service delivery costs from the acquisition calculation, then use them when assessing the contribution each customer produces.

Count new paying customers in the denominator, with an agreed definition such as a signed contract and first payment, and keep renewals or additional projects from existing clients separate.

How do you calculate customer acquisition cost for a services business?

Take a hypothetical UK services business using the following assumed figures for a mature enquiry cohort.

A cohort is a group of enquiries that arrived during the same period, followed through until their outcomes can be assessed.

The costs below cover acquiring and working that group, including unsuccessful enquiries and campaign spending that produced no enquiry.

Acquisition expense	Assumed cost
Marketing employee costs allocated to acquisition	£12,000
Agency fees and campaign expenditure	£9,000
Acquisition software allocation	£1,000
Sales employee costs allocated to the cohort	£8,000
Total acquisition spending	£30,000

Suppose this cohort produces 20 new paying customers.

Blended acquisition cost = £30,000 ÷ 20 = £1,500 per new customer.

That is the business-wide average across the acquisition routes included in the calculation.

It does not reveal which channel produced the strongest customers or whether the next customer will cost the same amount to acquire.

Avoid dividing this quarter's spending by this quarter's wins without checking the sales cycle, since those wins may have come from enquiries generated several months earlier.

Where customer-level cost allocation is unavailable, a period-based calculation can still provide a baseline, but label it as such and show the timing mismatch alongside it.

What is the difference between blended and channel CAC?

Blended CAC shows the combined cost of acquisition across the business, while channel CAC separates routes such as paid search and partner referrals.

Continue the hypothetical example by assuming £18,000 of the total costs are attributable or consistently allocated to paid search, which produced six customers.

That channel's fully loaded acquisition cost is £3,000 per customer.

The remaining £12,000 is attributable or allocated to partner referrals, which produced 14 customers, giving approximately £857 per customer.

The blended figure of £1,500 conceals that difference, so it cannot tell you whether increasing paid search spending would be affordable.

Channel comparisons need matching cost definitions, otherwise one report may include media spend alone while another includes employee and sales costs.

A campaign's cost per lead also uses a different denominator, and a low enquiry cost can still produce expensive customers when few enquiries convert.

Keep a recorded attribution rule, such as the first known acquisition source, and acknowledge assisted channels separately so the same customer is not counted twice.

Direct website visits and missing source fields should remain visible in reporting, without being assigned to a channel simply to complete the totals.

What if your data is incomplete?

You can build an initial calculation from available records, provided it shows the limits of what has been counted.

Record missing payroll allocations, untracked enquiries and unresolved sales opportunities alongside the result, then specify who will repair each gap.

A reconciled total of paying customers gives you a blended denominator even when some acquisition sources are unknown, although channel comparisons remain limited.

Timing is a separate issue: a recent cohort with open proposals has not yet produced its final number of customers.

Compare cohorts at similar stages of maturity, and retain the original acquisition costs as later wins are added.

If nobody can connect enquiries to paying customers, the first requirement is ownership of that measurement work.

The wider diagnosis of why marketing spend is not generating leads can help you assess whether the break sits in demand generation, website conversion or follow-up.

How much can you afford to spend on a new customer?

An acquisition figure only supports a decision when you compare it with the contribution a customer can generate and when that contribution reaches the bank.

Using another assumption for the same hypothetical business, suppose the first engagement produces £5,000 in revenue and requires £2,500 in delivery costs, excluding acquisition costs already counted.

That leaves £2,500 in contribution before acquisition, or a contribution margin of 50%.

After the £1,500 blended acquisition cost, £1,000 remains to cover other fixed costs and profit.

For a services firm, delivery costs can include subcontractors and the staff capacity required to fulfil the engagement, even where salaries are paid regardless of the individual contract.

Do not justify an expensive acquisition route using hoped-for repeat work, and assess repeat contribution using your own customer history where it exists.

Acquisition payback also depends on payment terms and collection, so a signed contract does not mean its contribution is available to fund payroll immediately.

How does the calculation change the hiring decision?

Your customer acquisition cost establishes the starting economics, while the hiring decision requires a separate view of what the additional person is expected to change.

If qualified enquiries wait for follow-up, investigate sales capacity and ownership before assuming that another marketer will resolve the delay.

If the business converts suitable enquiries profitably but cannot deliver recurring marketing work, an additional marketer may address the constraint.

A senior hire can also be justified when the team needs ongoing leadership, commercial judgement or authority to coordinate work across functions.

Write the role around that requirement, then assess its full employment cost alongside any extra campaign spending the person would manage.

Incremental acquisition cost = additional acquisition spending ÷ additional new customers.

Use scenarios to test the decision, showing the additional customers needed, their expected contribution and the cash required before payment arrives.

Keep those assumptions separate from measured performance, and check whether sales and delivery capacity could support the proposed increase.

A higher average acquisition cost after hiring is not automatically a poor outcome if the business gains more profitable customers, while a lower average can accompany shrinking customer numbers.

An agency can also be the right answer when you need specialist execution and already have someone internally who can direct and assess the work.

The guide to what to put in place before hiring a marketing director sets out the operating foundations that let a senior hire take responsibility.

When is The Growth Install an alternative to hiring?

The Growth Install is an option when the business needs defined growth workflows installed and handed over to the people who will own them, before committing to a permanent marketing role.

Founder Engine starts with the work and measurement, then agrees three areas to improve.

The engagement runs for 90 days and installs three agreed growth workflows, each in one agreed area, on your own accounts, with tracking and a dashboard.

Your business owns its accounts and systems, and the engagement focuses on the team's ability to keep operating the agreed workflows.

Its scope is limited to those workflows, so assess whether you also need permanent leadership or additional execution capacity.

What do founders ask before approving a marketing hire?

Do I need perfect data before deciding whether to hire?

You need enough evidence to identify the work the role should own and assess its cost. An initial calculation can support that decision if missing costs and unresolved customer outcomes remain visible. If the gaps could change the conclusion, assign the measurement work before approving the role.

Should I use cost per lead to judge whether marketing is working?

Cost per lead helps assess enquiry generation, but it does not show the cost of winning a paying customer. Track the conversion from enquiry to customer and include the sales effort required. Compare the resulting acquisition economics with customer contribution and cash collection.

Do I include the new marketer's whole salary?

Include the share of employment costs allocated to acquisition when calculating the ongoing acquisition metric. For the hiring decision itself, assess the full cost of employing the person and the wider responsibilities the role will cover. Record the allocation rule so it remains consistent between reporting periods.

Should I hire if one channel is too expensive?

A costly channel may need changes to targeting, the offer or sales conversion before additional staffing will help. A hire is justified when the recurring work and authority needed to improve performance belong in that role. Specialist agency support or a defined workflow engagement may fit a narrower requirement.

If you want help working out where growth is getting stuck, talk to Founder Engine.