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What is CPA (Cost Per Acquisition)?
CPA measures how much you pay for a conversion. Learn the formula, pitfalls, and how creative/feed changes lower CPA.
Brief Definition
CPA is how much you pay for a defined conversion (purchase, lead). It’s a core efficiency metric for performance marketing.
Understanding CPA
CPA depends on click costs and conversion rate. Boosting clarity and product relevance with catalog ads improves conversion, reducing CPA even at steady CPCs.
Why CPA (Cost Per Acquisition) matters
CPA matters because it sets clear guardrails for spend and provides a simple metric that teams can track weekly across campaigns and channels. When conversion values are similar, CPA enables apples-to-apples comparison across tactics and placements without the complexity of ROAS calculations. Monitoring CPA helps ensure acquisition costs stay within profitable ranges tied to your unit economics and contribution margin.
- Budgeting: Sets guardrails for spend
- Comparison: Useful across tactics with the same conversion definition
- Simplicity: Easy for teams to track weekly
How to Calculate CPA
- Formula: CPA = Ad Spend ÷ Number of Conversions
- Read by campaign/placement and by product set for accuracy.
Key Takeaways
- CPA (cost per acquisition) is ad spend divided by conversions; it shows cost efficiency per desired action.
- Lower CPA by improving CTR, conversion rates, and feed/creative relevance.
- Set CPA targets based on LTV, margin, and acceptable payback periods.
- Track CPA by channel, audience, and product category to identify efficient opportunities.
