Platform · Metrics · CPA
CPA: Cost per acquisition
What you pay for a conversion you defined: purchase, lead, install, booking. The media-level cost, not the full cost of a customer.
What it is
Cost per acquisition is spend divided by the conversions you told the platform to count. It is only as honest as that conversion. A lead CPA is not a customer CPA. A purchase CPA that ignores returns is not a contribution margin.
Why it is worth tracking
CPA is the number media teams live in. It is also the number that lies when the pixel is wrong, the conversion is a micro-event, or sales and marketing costs sit outside the ad account. Operators treat CPA as a media signal, then check it against CAC and LTV before they scale.
How to read it
A single number is not a brief. These splits are what change the work.
CPA over cap, CTR weak
You are paying for impressions that never become clicks. Creative first.
CPA over cap, CTR fine, conversion rate weak
Traffic is arriving. The page, offer, or checkout is the leak. Draft the landing path, not another ad.
CPA under cap, LTV:CAC still poor
You are buying cheap conversions that do not become valuable customers. Change who you acquire, not only how cheaply.
What the Operator does
Diagnose, act, then draft. The stats pick the job. Brand voice stays locked.
Diagnose
The Operator asks which conversion CPA is using, then reads it with CTR, conversion rate, and AOV. It will not scale a lead campaign as if it were purchase CPA.
Act
Pause combinations that miss CPA at real spend. Move budget to those that clear the cap with stable conversion quality. Flag when the tracked conversion is too shallow to steer on.
Draft
If CPA is failing on creative, draft new ads from winners. If it is failing after the click, draft landing, offer, and checkout copy. The Operator picks the surface the numbers point to.
Example brief
“Meta purchase CPA in Malaysia is 28% over cap. CTR is 1.2% (fine). LP conversion rate fell from 2.8% to 1.1% after a promo ended. Rewrite the landing hero and offer module for everyday value, not the old 20% off. Keep ads that still click.”
Paste a brief like this into a Basis Operator. Connected account context and brand rules apply automatically.
Related metrics
Read it with these, or you will optimize the wrong surface.