Gross margin per customer
What a single customer pays you, minus what that customer costs you to serve.
For an AI product the main variable cost is LLM tokens. Gross margin per customer = subscription revenue from that customer − their LLM cost over the same period. Because token usage varies wildly between customers on a flat price, your average margin can look healthy while individual customers are deeply unprofitable.
Why it matters
It's the number that decides whether growth makes you money or costs you money. Tracking it per customer — not just on average — is the only way to catch the accounts quietly eating your margin.
Example
A customer on a $49/mo plan who runs up $12 of LLM cost has a gross margin of $37 (76%). The same plan with a power user at $61 of cost is −$12 — a 24% loss on that one account.
Calculate it with the free margin calculator →
Related terms