Target CPA
Target CPA is a Smart Bidding strategy that aims to maximize conversions while keeping average cost per acquisition at your specified target.
What does Target CPA actually mean?
Target CPA (tCPA) is the conversion-volume counterpart to Target ROAS. The algorithm aims to maximize total conversions while keeping average CPA at your specified target. Used heavily for lead-gen, app installs and SaaS trial signups where every conversion has roughly equal value (vs. ecom where order value varies).
Like tROAS, tCPA needs at least 30-50 conversions per month per campaign to perform. Setting CPA too low for the auction reality starves the campaign: the algorithm raises bids to the target, can't find impressions, and spend collapses.
Most B2B and SaaS performance teams use tCPA on Google Search and PMax with target levels derived from lead-to-customer rate × ACV × gross margin. Adjusting tCPA up by 10-20% periodically to test scale (does spend grow, does CPA hold?) is a standard optimization rhythm.
Example
A SaaS company sets Target CPA = $80 on a Google Search campaign. The algorithm bids to maintain $80 average CPA across the month while spending the budget. It sometimes hits $60 and sometimes $110, averaging close to $80.
When it matters
Target CPA is the dominant bid strategy for B2B and SaaS lead-gen. Set it from your unit economics; test scaling it up periodically.
Related terms
Smart Bidding
Smart Bidding is Google's family of automated, ML-driven bid strategies: Target CPA, Target ROAS, Maximize Conversions, Maximize Conversion Value.
Target ROAS
Target ROAS is a Smart Bidding strategy on Google (and Meta's equivalent on Advantage+) that sets bids to hit a specified return on ad spend.
CPA
CPA is the cost to drive one conversion event: a purchase, signup, lead or install. It's the universal performance metric.
CPL
CPL is the cost to acquire one lead, typically a form submission, demo request, or email signup. The dominant B2B and SaaS performance metric.
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