What Is CPA (Cost per Acquisition)?
CPA (Cost per Acquisition) is the ad spend required to generate one conversion, usually a purchase, lead, signup, or install. It's the operational number ad platforms optimise toward and the number that decides whether a campaign can scale profitably.
Also known as: cost per acquisition, cost per action, cpa marketing, cpa formula, target cpa. This page answers "what is CPA", CPA formula,CPA calculation, and CPA benchmarks for Bangladesh and global performance marketing teams.
Formula
The 'conversion' must be defined the same way every time, if you sometimes count leads and sometimes count qualified leads, CPA becomes meaningless. Pick one primary conversion per campaign objective and stick to it.
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Your CPA
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Worked example
You spend $2,400 on a lead-gen campaign and Meta reports 60 leads. CPA = $2,400 ÷ 60 = $40 per lead. If your sales team closes 20% of leads at $600 gross profit each, contribution per lead is $600 × 20% = $120, so $40 CPA is healthy. If close rate drops to 5%, contribution is $30 and you lose money at the same CPA.
Benchmarks
- D2C ecommerce (Meta): $15 to $45 CPA at $60+ AOV is typical breakeven zone.
- B2B lead-gen (LinkedIn / Meta): $30 to $120 per marketing-qualified lead.
- SaaS free trial: $8 to $40 per signup; scale gated by trial→paid conversion.
- Local services (Google Ads): $20 to $80 per lead depending on category.
WordStream's US Google Ads benchmark study reports an average Search CPA of $66.69 across industries, with Employment Services ~$132 and Auto ~$34 as the extremes.
Why it matters
CPA is the honest gate for scaling. Every ad platform will happily spend more of your money at a rising CPA, most auto-bid strategies do exactly that. Setting a CPA ceiling tied to gross margin and close rate is how you stop the algorithm from turning your budget into low-quality volume.
Common mistakes
- 1.Setting a CPA target that ignores gross margin. Your CPA ceiling is a math problem, not a wish.
- 2.Chasing lower CPA by narrowing audiences. It works short-term, then CPMs explode and CPA rebounds.
- 3.Ignoring the funnel below the ad. A great ad + a broken landing page = high CPA. Fix the landing page first, always.
- 4.Comparing platform CPA and CRM CPA as equal. Platform CPA counts view-through and same-user cross-device; CRM does not.
Put CPA to work
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Related services
FAQs about CPA
What is a good CPA?
A CPA below your contribution margin per customer. If a new customer earns you $100 of gross profit on the first order, any CPA under $100 buys growth, anything over $100 buys losses.
What's the difference between CPA and CAC?
CPA is per platform-reported action. CAC (Customer Acquisition Cost) is total marketing + sales spend ÷ new customers acquired, the company-level number your CFO uses.
How do I lower CPA?
In order of impact: (1) better creative (raises CTR, lowers CPC), (2) better landing page (raises CVR), (3) better offer, (4) broader audience with strong signal, narrower is not automatically cheaper.
Why does my CPA change every week?
Small conversion counts. Below ~50 conversions per ad set, weekly CPA swings ±30% are noise, not signal. Aggregate to 14- or 28-day windows to see the real trend.
Related terms
Revenue attributed to ads ÷ ad spend, the fastest efficiency read.
Spend divided by leads captured, a top-of-funnel efficiency metric.
Ad spend divided by clicks, what one click into your site costs.
% of clicks or sessions that complete the target action.
Average revenue per transaction, total revenue ÷ number of orders.
Lifetime value ÷ acquisition cost, the unit-economics gate for scaling.
How credit for a conversion is assigned across ad touchpoints.
Meta's AI-driven campaign setup that automates targeting and placements.