ROI Analysis: AI vs Manual Revenue Recognition | Vibe Accounting in Public

We've had a lot of jaw drop moments building our AI agent. For Day 12 of Vibe Accounting, I wanted to move beyond the "wow" and run a quick, back-of-the-napkin ROI calculation on one of them.

Let's take that complex revenue recognition ruleset from one of our vibe accounting sessions before - the one with blended amortization, multi-currency FX, and custom tax logic.

I asked a senior accountant on my team to estimate the time for a one-off build like that in a spreadsheet. Their honest answer? About two full days, so roughly 16 hours of a highly skilled professional's time. If we use a conservative, fully-loaded rate of, say, $100/hour, you're looking at a $1,600 internal cost for a single and brittle automation.

Now, let's look at the Vibe Accounting workflow. We already timed this. The AI agent built the entire rule after a short prompt, and the total time for me to guide and review it was 25 minutes. The actual API cost for the interaction was trivial. When you run the numbers on that, the new all-in cost is under $50.

We're not talking about a 10% or 20% improvement here. We went from a two day, sixteen hundred dollar process to a 25 minute, $50 task. That's a 97% reduction in both cost and time.

These numbers will vary of course, but the order of magnitude leap in efficiency is the real story. AI agents will fundamentally rewrite the unit economics of the finance function and that creates an entirely new competitive advantage for a business.