| Cloud Infrastructure & Hosting |
Variable |
Model as 3.0% of revenue in the first year, declining to 2.0% by the fifth year. |
Treating hosting as fully fixed while user activity and data volume rise. |
| Payment Processing Fees |
Variable |
Model as 1.5% of revenue in the first year, improving to 1.0% by the fifth year. |
Forgetting that card fees scale directly with paid subscriptions and transaction revenue. |
| Sales Commissions |
Variable |
Model as 4.0% of revenue in the first year, easing to 3.0% by the fifth year. |
Putting commissions in fixed payroll and overstating contribution margin. |
| Third-Party API Usage |
Variable |
Model as 1.0% of revenue in the first year, declining to 0.6% by the fifth year. |
Ignoring per-use vendor charges as customer activity grows. |
| Annual Marketing Budget |
Semi-variable |
Pace spend from $250,000 in the first year to $1,100,000 in the fifth year, but treat committed campaigns as burn. |
Assuming marketing can be cut instantly after contracts, campaigns, or channels are locked. |
| CEO, Engineering, Sales, Marketing, and Support Payroll |
Semi-fixed |
Step payroll up as full-time headcount rises from 4.0 FTE in the first year to 15.0 FTE in the fifth year. |
Calling all payroll fixed and missing hiring jumps tied to scale and support load. |
| Office Rent |
Fixed |
Carry $3,000 per month from Month 1 through Month 60 within the current planning range. |
Linking rent to revenue even though the lease does not move with sales volume. |
| Internal Software Licenses, Legal & Accounting, Utilities, Insurance, and Admin |
Fixed |
Carry the monthly overhead base at $4,300 from Month 1 through Month 60. |
Spreading small fixed overhead across customers and treating it like usage spend. |