Cost Per Acquisition (CPA)

Change the conversion and the number changes with it. The same €12,000 might be 300 form fills (€40 CPA), 30 booked meetings (€400) or 9 customers (€1,333). All three are correct. Only the last one can be compared with what a customer is worth.

• CPL, cost per lead

  Spend over leads, usually form fills. The platform's favourite because it is cheap and immediate. See cost per lead.

• CPA, cost per acquisition

  Spend over whichever conversion you defined. The flexible middle: a qualified lead, a call, a booking, a trial.

• CAC, customer acquisition cost

  All acquisition cost over new customers. The one finance recognises. See customer acquisition cost.

Google Ads and Meta both offer bidding that aims at a target cost per conversion. The algorithm is only as good as the conversion it is aimed at. Aim it at form fills and it finds the cheapest form fillers, who are rarely the people who buy. Aim it at qualified leads or closed deals, sent back from the CRM with their values, and it finds buyers at a CPA that means something.

• Send the right conversion backQualified leads, booked meetings and closed deals go to the platforms as conversions through their APIs, so target CPA is measured on them. See offline conversion tracking.
• Count all of themA conversion the browser blocked never reaches the algorithm. Server-side capture keeps the count complete, so the bid strategy learns from every acquisition.
• Mind the delayA deal that closes in week five arrives as a conversion in week five. Bid strategies need enough volume and a long enough window to learn from late conversions.

Below what the acquired thing is worth, by enough margin to fund everything else. For a customer, that means CPA against the customer's gross margin over their lifetime. For a booked meeting, CPA against the meeting's close rate times the deal value. A €400 meeting is cheap if one in four closes at €12,000 and expensive if one in twenty does. Benchmarks by industry are a distraction; the CPA calculator puts your own numbers side by side.

CPA is a ratio with a moving definition. Decide which conversion counts as the acquisition, make sure every one of them is recorded and sent back to the platforms, and compare the cost to what the acquisition is worth. The platform's own CPA, measured on form fills, is the least useful version of the number.