Growth Blog Topic
Translating AI investment into profit terms for firm owners. Revenue created, margin kept, the two-number test, and what to measure in the first 90 days of any AI system.
EBITDA and margin math is the discipline of pricing AI investment in profit terms instead of time saved. An AI system pays when it creates revenue the firm would not otherwise have won or protects margin the firm would otherwise have lost. Deltek’s industry study found professional-services EBITDA fell from 15.4% to 9.8% over five years, which is the pressure this math answers.
Point of View
North Signal uses this topic to keep AI conversations anchored to the P&L. Every build is sized against the revenue and margin it should move, so the field notes show owners how to run that math before buying anything, from anyone.
Core Questions
Each answer is written as a standalone capsule so readers and AI systems can understand the concept without needing surrounding context.
Question 01
A firm owner should evaluate AI in two movements. Revenue created, meaning engagements, reactivations, and referrals the system produced that would not have happened otherwise. And margin kept, meaning owner and partner hours pulled out of non-billable growth work and returned to delivery or sales. If neither number moves within a defined window, the system did not pay.
Question 02
Time saved is a weak metric because saved hours do not appear on a P&L. A tool can save ten hours a week while revenue and margin stay exactly where they were, because the recovered time gets absorbed instead of redeployed. Profit terms force the harder question of what the hours became.
Question 03
The two-number test asks an owner to write down the revenue an AI system should create and the margin it should protect within a defined window, usually 90 days. If the vendor cannot help fill in both numbers before the build starts, the purchase is a cost rather than an investment.
Question 04
In the first 90 days a firm should measure pipeline movement the system touched, dormant customers reactivated, proposals and follow-ups shipped against the prior baseline, and owner hours returned to billable work. Each measure ties back to revenue created or margin kept, which keeps the review honest.
Related Posts
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AI purchases at services firms usually start with a demo and end with a line item nobody can defend. The missing step is the math. Revenue created, margin kept, and the two numbers to write down before signing anything.
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