A good cost per acquisition is below the value of the acquisition: for a one-time sale, below the contribution margin of the order; for a customer, below a sensible share of lifetime value; for a lead, below the value of a lead given your close rate. Averages ($38 on Meta ecommerce panels, $67 to $76 per lead on Google Search) are context, never targets.
What moves it
CPA moves with conversion rate and CPC, and it rises as spend increases within a channel because the cheapest conversions come first. Marginal CPA, the cost of the next conversion, is the number that should set budgets. Target CPA bidding aims at an average and will trade volume for it.
Google Search benchmarks, September 17, 2026
| Average CPC | $4.30 to $5.50 across industries; Legal, Insurance, and Financial Services from about $15 to over $23; Ecommerce and Arts under $2 |
| Average CTR | 6 to 7 percent across industries in 2026 studies; under 5 percent in Legal and Industrial, above 9 percent in Dating and Finance |
| Conversion rate | 5.7 to 8.2 percent (click-based) across industries; highly dependent on what counts as a conversion |
| Cost per lead | $67 to $76 blended; $130 to $300 in Legal, Insurance, and Financial Services |
| ROAS | About 4x blended in agency-reported data; ecommerce accounts commonly target 4x to 6x |
Sources and every other channel: Google Search benchmarks.
Run your own numbers with the CPA and ROAS calculator.
Agency Echelon. "What is a good CPA?" Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/questions/what-is-a-good-cpa/