How to calculate cost per customer from leads
Full conversion rate = valid lead rate × close rate
Cost per customer = cost per lead ÷ full conversion rate
Example: cost per lead 40, 70% of leads are valid (correct number, genuinely interested), and sales closes 15% of the valid ones. Conversion = 0.7 × 0.15 = 10.5%. So cost per customer = 40 ÷ 0.105 = 381, more than 9 times the cost per lead.
Why cost per lead alone is misleading
Meta's algorithm looks for the cheapest lead, not the best customer. A campaign at 25 per lead may bring weak leads who never answer, while one at 60 brings serious buyers. Compare them on cost per lead and you'll switch off the better campaign. Calculate cost per customer per campaign, or at least per audience and form.
Read Facebook Lead Ads: Why Lead Quality Is Poor and How to Improve It for ways to raise lead quality inside the form itself, such as custom questions and the "higher intent" form type.
How to find your valid lead rate and close rate
- Export the last two weeks of leads to a sheet and add a status column: valid, wrong number, not interested, sold.
- Valid rate = valid ÷ total leads. Close rate = sales ÷ valid leads.
- Repeat per campaign if you can, because the gap between audiences is sometimes large.
What if cost per customer is higher than your profit?
Start with the weaker rate. If valid leads are few, the problem is the ad or the form. If valid leads are fine but closing is weak, it's usually response speed or the sales pitch. Calling a lead within the first hour clearly lifts the close rate. For an alternative to lead forms, read WhatsApp Message Campaigns on Facebook: Measure Cost per Order, Not per Conversation.