Metrics

What is cost per acquisition (CPA)?

CPA = ad spend ÷ conversions. It's what you pay, on average, for each sale or signup.

Flat monthly price, no revenue tax
No annual contract
Tracking starts the minute the snippet is live

Cost per acquisition tells you how much advertising it takes to produce one conversion. If you spent $2,000 and got 40 sales, your CPA is $50. Variants measure different conversions: cost per lead (CPL) divides by leads, and customer acquisition cost (CAC) usually includes all sales and marketing costs, not just ads.

A useful refinement is cost per new customer: spend divided by first-time buyers only. Repeat purchases make CPA look better than the real cost of acquiring someone new, especially for brands with loyal customers who come back through retargeting.

The problem

Why this matters for your ad budget

CPA calculated from platform conversions is often lower than reality, because platforms over-claim. And counting returning customers as acquisitions hides what new customers really cost.

Your CPA should come from your own data.

See true CPA and cost per new customer per ad

Create your account, install one snippet and see it on your own leads and sales.

Flat monthly price, no revenue tax
No annual contract
Tracking starts the minute the snippet is live

Create your account

Key takeaways

CPA

Spend ÷ conversions.

CPL

Spend ÷ new leads.

Cost per new customer

Spend ÷ first-time buyers.

All of this is built in, ready on day one.

Try it on your own data

Use cases

How marketers use this

Cost per new customer

Separate new from returning buyers.

CPL and CPA

Every row shows cost per lead and per sale.

Targets that fit

Set CPA targets from real LTV.

Try it on your own data

Flat monthly price, no revenue tax
No annual contract
Tracking starts the minute the snippet is live

Why BrainyMetrics

From theory to your own numbers

Everything in this guide is built into BrainyMetrics, working on your real ads, leads and sales.

Without BrainyMetrics

With BrainyMetrics

Meta, Google and TikTok each claim the same sale, so platform totals add up to more than your bank account.

Each sale is counted once, from your own checkout data, and reconciled against what each platform claims.

Analytics gives the last click all the credit, so the ads that start journeys look like they lose money.

Seven attribution models are computed for every conversion, so you can compare first click, last click and everything between.

Phone calls and booked calls are a black box. You know they happened, not which ad caused them.

Calls and bookings are matched to the visitor's session and the ad behind it, then tracked through qualified and closed.

Ad blockers, Safari and cross-domain checkouts quietly break your data.

A first-party tracking subdomain, server-set cookies and cross-domain linking keep journeys intact.

Spend lives in one tab, revenue in another, and ROAS is a spreadsheet you rebuild every Monday.

Spend syncs hourly and sits next to attributed revenue, so ROAS, CPA and profit are on every row, down to the ad.

Ad algorithms optimise on the few conversions their pixel happens to see.

Real purchases and leads are sent back to the ad platforms' conversion APIs, deduplicated against the pixel.

Stop guessing which marketing pays.

Try it on your own data

Getting started

Put this guide into practice in four steps

No migration project and no agency retainer. Here is the whole path from sign-up to your first attributed sale.

1
Create your account
Sign up, name your workspace and pick the plan that fits. Your tracking snippet is waiting under Settings → Install.
2
Install tracko.js
Paste one snippet into your site's head, or add it with Google Tag Manager, WordPress or your funnel builder's tracking code box.
3
Connect revenue and ads
Connect Stripe, Shopify, your funnel builder or calendar, then Meta, Google or TikTok for hourly spend. Most connections take a click.
4
Watch the first sale land
The setup checklist ticks itself off as data arrives. Your next lead or sale shows up with its full journey and the ad that earned it.

Create your account

Flat monthly price, no revenue tax
No annual contract
Tracking starts the minute the snippet is live

One account

Everything else that comes with it

Tracking, attribution, calls, spend and revenue analytics share one data model, so each feature makes the others more accurate.

Multi-touch attribution

Seven models side by side, down to the ad.

First-party tracking

Your own subdomain and server-set cookies.

Call tracking

Dynamic numbers matched to the click behind each call.

ROAS and profit

Hourly spend sync joined with real revenue.

Conversion APIs

Feed real sales back to nine ad platforms.

Customer journeys

Every visit, ad, order and call per person.

LTV and cohorts

Lifetime value by the channel that acquired them.

Funnels

Drop-offs and cost per step, by ad.

Create your account and start tracking today.

Create your account

Frequently asked questions

Common questions about this topic, setup and pricing.

The fastest answer is your own data

Create an account, install the snippet and see how BrainyMetrics handles your real traffic.

Get started

What is a good CPA?

One that is comfortably below the profit a customer generates, ideally measured over their lifetime rather than the first order.

How long does setup take?

The basics take minutes: paste the snippet, connect your checkout or funnel builder, and connect your ad accounts. The setup checklist in your dashboard ticks each step off as data arrives, so you always know what's left.

Do I need a developer?

Usually not. The snippet can go in through Google Tag Manager, WordPress or your funnel builder's tracking code settings, and most revenue sources connect with a click or a webhook URL you paste. The developer guide covers the JavaScript and server API if you do have a developer.

Does the price go up as I grow?

No. Plans are a flat monthly or yearly price. We never bill a percentage of revenue or ad spend, and you can switch, pause or cancel from the Billing page without a call.

Does tracking stop if I hit a plan limit?

No. Plans limit dashboard modules and things like integrations or workspaces; tracko.js, webhooks and syncs keep collecting data, so nothing is lost if you upgrade later.

Is it privacy friendly?

Yes. BrainyMetrics supports consent modes, works with your consent banner, respects Global Privacy Control and handles sensitive form fields strictly. Data is first-party: it belongs to your workspace, not an ad network.