Customer Acquisition Cost (CAC)

A consulting software company discovered that CAC varied dramatically by industry vertical. Financial services companies cost £12,000 to acquire but had 3-year average contracts. Manufacturing companies cost £7,000 to acquire but had 1.5-year contracts. This analysis revealed that the apparently 'expensive' financial services vertical was actually more profitable. The company shifted focus to that vertical and improved overall unit economics.

B2B growth teams live and die by CAC. If your CAC is £10,000 but your average customer lifetime value is £30,000, you have room to grow profitably. If your CAC is £10,000 but your LTV is £12,000, you have very thin margins and any increase in customer churn or decrease in average deal size could destroy profitability.

Understanding your CAC helps you make investment decisions. Should you hire more sales people? Increase advertising spend? Build more content? The answer partly depends on your CAC and whether you can improve it. If your CAC is trending upward, you need to diagnose why: are customers becoming harder to acquire, or are you targeting less-qualified markets?

CAC also reveals channel efficiency. If you calculate CAC by marketing channel, you might discover that content marketing delivers customers at £3,000 CAC while paid advertising delivers at £8,000 CAC. This doesn't mean you should eliminate paid advertising - those channels might deliver customers at different lifecycle values or risk profiles - but it informs your strategy.

A services company calculated CAC of £8,000 with 18-month payback. They implemented marketing automation and improved lead qualification, reducing the time from lead to opportunity from 8 weeks to 4 weeks. This allowed their sales team to sell more efficiently, and CAC improved to £6,500 without changing marketing spend. The efficiency gain alone improved business economics.

Calculate your CAC regularly - monthly, quarterly, and annually. Set targets for what CAC should be given your pricing and desired margins. A common rule of thumb is that your CAC should be paid back within 6-12 months through gross profit from that customer. If your average contract value is £5,000 per year with 70% gross margin, your CAC should ideally be under £3,500.

Segment your CAC by channel and cohort. What's the CAC for customers acquired through your website versus LinkedIn versus referrals? Which customer segments have the best unit economics? A customer from a referral might have £2,000 CAC; a customer from enterprise sales might have £15,000 CAC. Understanding these differences guides your strategy.

Measure CAC payback period: how long does it take for a customer to generate enough profit to cover the cost of acquiring them? If your payback period extends beyond 24 months, your business won't grow sustainably. Conversely, if your payback period is 6 months, you can reinvest profits quickly to fuel growth.

Customer Acquisition Cost (CAC) is what it costs you, on average, to win one new customer. Add up everything you spent on sales and marketing over a period, then divide by the number of customers you brought in. Spend £100,000 in a quarter and land 50 customers, and your CAC is £2,000. Simple sum, but it's one of the numbers a business lives or dies by, because it sets the ceiling on how profitably you can grow.

The spend you count is broader than ad budget. It's the advertising, the content, the events, the software, the salespeople's salaries and commissions, and usually the cost of onboarding and supporting that customer in their first months. Leave bits out and your CAC looks flattering and lies to you.

What counts as a good CAC depends entirely on what a customer is worth to you. A low-touch, self-serve SaaS might acquire for £500-2,000. An enterprise deal with a six-month sales cycle might cost £50,000 to win, and that's fine if the contract is large and sticky. The only question that matters: is your CAC comfortably below the lifetime value of the customer it buys?

Why it matters

CAC tells you whether your growth is sustainable or just expensive. If you spend £10,000 to win a customer worth £30,000, you have room to grow. If that customer is worth £12,000, you're one bad month of churn away from losing money on every sale.

It also tells you where to put your next pound. Break CAC down by channel and you might find content brings customers in at £3,000 while paid ads cost £8,000. That doesn't always mean kill the ads, those customers may be worth more or convert faster, but you can't make the call until you can see the number per channel.

How to apply it

Calculate CAC on a regular cadence and set a target tied to your pricing and margins. A common rule: recover your CAC within 6-12 months of gross profit. If a contract is £5,000 a year at 70% margin, you want CAC under about £3,500.

Then segment it, by channel, by cohort, by deal source, and watch the payback period (how long until a customer's profit covers what you paid to get them). Push past roughly 24 months and growth gets painful; hit 6 months and you can recycle profit straight back into acquisition.

Examples

The whole exercise falls apart if your spend and your customer counts live in different places, so the practical work is getting both into one view.

• Tagging spend to the source. Say you're running outbound and inbound side by side in Pipedrive and you tag every won deal with the channel that originated it. Export a quarter of closed-won deals, line them up against what each channel cost, and your per-channel CAC stops being a guess. You might find referrals close at £2,000 a head while cold outbound sits at £9,000, and suddenly the obvious thing to scale is obvious.

• Watching CAC as a live number. Say you wire your ad spend, your sales-team cost and your new-customer count into a dashboard in Databox. Instead of recalculating CAC by hand each quarter, you get it as a trend line, and the month it starts creeping upward you go looking for the cause (harder-to-reach buyers, a weaker offer) before it eats your margin rather than after.

• Cutting the cost to win, not the spend. Say your team runs deals through Close and you notice leads sit untouched for a week before anyone calls. Tighten the qualification and follow-up so reps spend their time on deals that actually close, and the same marketing budget produces more customers, which is to say your CAC drops without you spending a penny less up front. The cheapest CAC improvement is usually efficiency, not a bigger budget.

A B2B software company tracked CAC by source. Content marketing delivered customers at £4,200 CAC with 18-month payback. LinkedIn advertising delivered at £6,800 CAC with 24-month payback. Enterprise sales delivered at £35,000 CAC with 30-month payback. The company increased content and demand generation investment, reduced reliance on enterprise sales, and improved overall CAC to £5,600 while maintaining revenue growth.