Quick definition
CPA (cost per acquisition) is the average amount an advertiser pays to gain one conversion, such as a sale or sign-up — total spend divided by acquisitions.
Advertising
Part of the SocialKit social media glossary — browse every term.
CPA stands for cost per acquisition (sometimes cost per action), a performance-advertising metric that measures how much you spend, on average, to produce one desired conversion. The formula is straightforward: total campaign spend divided by the number of acquisitions. What counts as an "acquisition" depends on the campaign goal — it might be a purchase, a subscription, an app install, or a completed sign-up. Because it ties spend directly to results rather than to impressions or clicks, CPA is a favourite bottom-of-funnel metric for advertisers who care about outcomes over reach.
Most major social ad platforms let advertisers optimise campaigns toward CPA, using conversion tracking and the platform’s algorithm to find users likely to complete the target action at the lowest cost. It’s often compared with CPC (cost per click) and CPM (cost per thousand impressions): CPM and CPC measure earlier funnel stages, while CPA measures the outcome that actually matters to the bottom line. A campaign can have a cheap CPC but a poor CPA if the clicks don’t convert — which is why acquisition cost is watched closely on paid social.
CPA is most meaningful when compared against the value of an acquisition — a customer’s average order value or lifetime value. A CPA that’s below what a customer is worth signals a profitable campaign; a CPA above it signals a loss, no matter how good the click metrics look. Advertisers lower CPA by improving targeting, tightening creative, and optimising the landing page and checkout so more clicks turn into conversions. Comparing CPA across channels also shows where acquisition budget is working hardest.
Where SocialKit fits
SocialKit doesn’t run paid ad campaigns, but it schedules the organic content that lowers your reliance on paid acquisition — publishing to all 11 platforms from one calendar so more of your growth comes without a per-conversion cost.
€0.00 due today · cancel anytime · 7-day money-back guarantee
FAQ
Quick answers to the questions people ask most about this term.
SocialKit posts to all 11 platforms from one calendar and tracks how every post performs, so the numbers explain themselves. Try it free for 7 days.
€0.00 due today · cancel anytime · 7-day money-back guarantee