milestone 4/4 AI usage cost & contribution margin

Compare usage revenue with costs to calculate contribution margin.

AI Platform Economics · Calculate success rates and usage costs, prevent join fan-out, and reconcile split payments with refunds.

approach

Usage cost equals input tokens × input rate plus output tokens × output rate, divided by one million. These rates are fictional. Under this exercise’s rule, successful requests are chargeable; errors are excluded. Compare January billed revenue to January successful usage cost, not all-time billing.

SELECT
  r.model,
  ROUND(SUM(r.input_tokens*m.input_per_million+ r.output_tokens*m.output_per_million)/1000000.0,6) AS usage_cost
FROM ai_requests r
JOIN model_rates m ON m.model=r.model
WHERE r.status='success'
GROUP BY r.model;

data for this milestone