Staffing firms that employ contractors typically operate on thin margins (around 20%) and must pay contractor salaries at month-end regardless of when clients pay.

Waiting 30-45+ days after invoicing would force them to pre-fund multiple months of payroll, creating cash-flow risk. Early payment (invoicing on day 1 with net-15 terms, or a one-month deposit) ensures funds are available when salaries are due, protecting the firm's ability to operate and pay developers on time.