CAC
Customer Acquisition Cost (CAC) is total acquisition spend divided by new customers won. Here's the formula, the benchmark ranges, and how to read it against LTV.
CAC (Customer Acquisition Cost)
CAC is total sales and marketing spend divided by the number of new customers acquired in the same period.
Customer Acquisition Cost measures what it costs, on average, to turn a stranger into a paying customer. It's the denominator of every profitability conversation: pair it with average order value, repeat rate, and gross margin and you have the economics of the store on one line.
There are two versions in active use. Paid CAC divides paid media spend by customers acquired through paid channels — useful for channel-level decisions. Blended CAC divides all acquisition spend (paid media, agency fees, tooling, sometimes salaries) by all new customers — the number a CFO cares about. Healthy online stores generally target CAC below one-third of customer lifetime value.
CAC sits in the family of ecommerce metrics that describe acquisition efficiency — alongside ROAS, payback period, and contribution margin. ROAS asks how much revenue a euro of ad spend returns; CAC asks how many customers it bought. The two move together but answer different questions.
The metric is deceptively simple. Most of the disagreement happens in the numerator: do you include agency retainers, influencer gifting, the Klaviyo bill, the in-house growth team's salary? Pick a definition, document it, and apply it consistently across months — otherwise trend lines lie.
CAC = Total Acquisition Spend / New Customers Acquired
Total Acquisition Spend
Acquisition spend
Sum of paid media, agency fees, acquisition tooling, and (for fully-loaded CAC) acquisition team salaries over the period.
New Customers Acquired
New customers
Count of customers placing their first order in the period. Returning buyers are excluded.
A Shopify apparel store spent €48,000 on Meta and Google Ads in October, plus €6,000 on an agency retainer and €2,000 on creative production. It acquired 1,400 first-time customers in the same month.
Paid media spend: €48,000
Agency retainer: €6,000
Creative production: €2,000
New customers: 1,400
→ Blended CAC = €56,000 / 1,400 = €40.00
A €40 CAC is workable if AOV is €70+ and the brand sees a second order within 90 days. If first-order contribution margin is below €40, the store is buying customers at a loss and betting on repeat purchases — a position that needs an LTV number to defend.
Benchmarks are useful for sanity-checking, not target-setting. CAC varies wildly by vertical because AOV and repeat rate vary wildly. A €120 CAC is brilliant for furniture and disastrous for socks. The table below gives realistic ranges by category for stores in the €1M–€15M revenue band.
Typical blended CAC ranges for online stores by vertical (€1M–€15M revenue band)
| Vertical | Typical AOV | Blended CAC range | Target LTV:CAC |
|---|---|---|---|
| Apparel & accessories | €60–€90 | €25–€45 | 3:1 |
| Beauty & skincare | €40–€70 | €20–€38 | 3.5:1 |
| Home & decor | €90–€160 | €40–€75 | 3:1 |
| Consumer electronics | €120–€300 | €55–€120 | 2.5:1 |
| Food & supplements (subscription) | €35–€60 | €28–€55 | 4:1 |
| Furniture | €400–€900 | €140–€280 | 2:1 |
Read the table as a sanity check on direction, not a target. If your CAC is at the top of the range for your vertical, the next question is whether repeat rate and AOV justify it. If it's at the bottom, the next question is whether you can scale spend without the number drifting up.
Frequently asked questions about CAC
Paid CAC divides paid media spend by customers acquired through paid channels — useful for evaluating Meta vs Google vs TikTok. Blended CAC divides total acquisition spend by all new customers, including organic and referral. Blended CAC is the number that actually predicts profitability; paid CAC is the number you optimise channel budgets with.
Depends on the audience. For board reporting, use fully-loaded CAC including in-house team salaries and tooling — that's what the business actually spends to acquire customers. For weekly marketing reviews, a media-only CAC is more actionable because salaries don't change week to week.
3:1 is the rule of thumb across most online retail verticals. Below 2:1 means you're not making enough per customer to justify the acquisition cost. Above 4:1 often means you're under-investing in growth and leaving market share on the table — counter-intuitive, but common.
ROAS measures revenue per euro of ad spend; CAC measures cost per new customer acquired. ROAS counts all revenue including returning buyers, which is why high ROAS can hide a broken acquisition engine. CAC strips that out by only counting first-time customers in the denominator.
CAC payback is how many months of gross profit per customer it takes to recover the acquisition cost. If CAC is €40 and you make €15 in gross profit per month per customer, payback is roughly 2.7 months. Under 6 months is healthy for most online retail; 12+ months means you're financing growth with working capital.
Usually because returning customers are inflating ROAS. As repeat purchase volume grows, paid campaigns increasingly serve existing buyers, pushing revenue (and ROAS) up while net-new customer acquisition stagnates. Segment campaigns by new vs returning to see the real trend.
There's no perfect answer. Last-click underweights upper-funnel channels like Meta prospecting; first-click overweights them. Most stores use a blended approach: track platform-reported CAC per channel for tactical decisions and rely on blended CAC (total spend / total new customers) for the strategic view.
Strictly speaking, no — discounts hit gross margin, not the acquisition budget. But if your acquisition strategy depends on a first-order discount (welcome offers, sign-up codes), include the discount cost in CAC to get an honest read. A €30 CAC with a €15 welcome discount is really a €45 cost-to-acquire.
Weekly at the paid-channel level for budget decisions, monthly at the blended level for board reporting, and quarterly against LTV for strategic decisions. Watch the 30-day rolling number rather than daily — paid campaigns have enough variance that daily CAC is mostly noise.
Directly. CAC is paid traffic cost divided by conversion rate, roughly. A 20% lift in checkout conversion drops CAC by about 17% with zero change in ad spend — which is why CRO is usually the highest-ROI lever once paid acquisition has scaled. It's cheaper to convert more of the traffic you're already paying for than to buy more traffic.
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