Customer Acquisition Cost (CAC)

What it is

Take everything you spent to get new patients in a period — ads, boosted posts, the agency, the printed cards, the referral incentive — and divide it by the number of new patients that period produced. That is your CAC. Most practices have never calculated it, and almost none calculate it per channel, which is where the useful version lives: Google might be costing you R400 a patient while Instagram costs R1,900.

Why it matters to your bottom line

• Until you know CAC you cannot tell a good month from a lucky one. Revenue went up, but did it go up more than what you paid to make it go up?
• CAC only means something next to what a patient is worth to you. R1,200 to acquire is ruinous if they never come back, and a bargain if they stay four years.
• Blended CAC hides the truth. One channel is almost always subsidising another, and you cannot cut the bad one until you can see it separately.

How it works here

1. Count the spend honestly

   Everything aimed at new patients, not just the ad platform invoice. Agency fees, creative, the discount on the introductory offer — all of it is acquisition cost.

2. Attribute the source

   Every enquiry that lands in the CRM carries where it came from. Without that, per-channel CAC is guesswork and you are back to a blended number that tells you nothing.

3. Divide, then compare

   Spend ÷ new patients, per channel, per month. The number on its own is neutral. Set against lifetime value it becomes the most important figure in the practice.

Questions owners ask

Do referrals count as acquisition cost?

If you paid for them — a voucher, a discount, a thank-you gift — yes, and they usually come out as the cheapest channel you have, which is an argument for spending more attention there rather than less.

My marketing is just me posting on Instagram. Is my CAC zero?

No. Your time is the most expensive input in the practice. Cost it at what an hour of your clinical time earns and the number stops looking free very quickly.

Related

• Lifetime Value (LTV)What one patient is worth across the whole relationship, not the first appointment — treatments, retail and referrals included.
• LTV:CAC RatioWhat a patient is worth divided by what they cost to get — the single number that says whether the business can scale.
• Cost Per Lead (CPL, CPC, CPM)What one enquiry costs you — and the three abbreviations every advertising platform reports it in.
• Lead GenerationTurning anonymous visitors into named people you can follow up — the Skin Assessment is the main tool for it here.