AI pays differently in each function, so measure each on its own numbers. Sales: meetings booked and pipeline per rep. Marketing: cost per lead, booked calls and time to first draft. Operations: throughput and rework. Finance: close time and errors caught. Evidence suggests back-office work often returns more than the visible front-office spend.
Key takeaways
- Each function needs its own ROI measure, drawn from a system it already uses.
- According to MIT NANDA's research, as reported by Fortune, more than half of generative AI budgets go to sales and marketing, yet the largest returns were found in back-office automation.
- Some of the strongest evidence comes from support and operations, where an AI assistant lifted newer agents most.
- Finance work needs the tightest checks, because AI can be confidently wrong on tasks outside its strengths.
- Compare functions per workflow, on the same formula and review period, never on headline percentages.
Where does AI pay most across the business?
Returns tend to be clearest where work is frequent, defined and measured: support, reporting, document checks and drafting. Budgets often flow the other way, towards visible sales and marketing tools. So the function spending most on AI is not always the one getting most from it. Measure each before moving budget.
Spending follows visibility. According to MIT NANDA's research, as reported by Fortune, more than half of generative AI budgets go to sales and marketing tools. Yet the largest returns were found in back-office automation. That does not mean front-office AI fails. It means it has to prove itself in pipeline, not in activity.
| Function | Typical workflows | ROI measure | Evidence |
|---|---|---|---|
| Sales | Account research, follow-ups, proposals | Meetings booked, pipeline per rep | Mixed; depends on the CRM data |
| Marketing | Drafts to a brief, reporting, ads | Cost per lead, booked calls, time to first draft | Strong for drafting speed |
| Operations | Support replies, client reports, delivery documents | Throughput, rework, time to approved work | Strong in support settings |
| Finance | Document checks, report drafts, contract summaries | Close time, errors caught, outside spend avoided | Promising, needs tight review |
What does AI ROI look like in sales?
In sales, AI pays when it gives reps more time with buyers and better preparation for each conversation. Measure meetings booked per rep, time from call to follow-up, proposal win rate and pipeline per rep. Activity counts, such as emails sent, rise easily and prove nothing on their own.
Good sales workflows are narrow. Research an account before a call. Draft a follow-up that answers the objection actually raised. Assemble a proposal from past wins. Each has an output a rep can check in minutes, and each feeds a number the CRM already holds.
Two cautions. First, the CRM has to record outcomes reliably, or the return cannot be seen. Second, anything sent to a prospect should pass a person first. For outbound, that means campaigns are loaded paused and a person launches them. The guide to weekly SDR performance reviews shows how to read the numbers that matter.
What does AI ROI look like in marketing?
Marketing returns show up first as speed, then as pipeline. Time to first draft usually falls quickly, while cost per lead and booked calls take longer to move. For organic work, add AI visibility and search demand won. Judge the function on booked calls and pipeline, not on content published.
The speed evidence is strong. According to MIT News, an experiment by Shakked Noy and Whitney Zhang, published in Science in 2023, found ChatGPT cut the time 453 professionals took on writing tasks by 40%. Quality, judged by independent evaluators, rose by 18%.
Speed is not return, though. More drafts can mean more output nobody needed. The return arrives when faster, better work reaches buyers and turns into booked calls and pipeline. The guide to tying AI work to pipeline covers the measurement chain from lead to deal.
What does AI ROI look like in operations?
In operations, AI pays through throughput and consistency: more requests handled per person, fewer errors and shorter time from request to approved work. Support, client reporting and delivery documents are common candidates. Some of the strongest published evidence for AI productivity comes from this kind of work.
According to a study of 5,179 customer support agents by Erik Brynjolfsson, Danielle Li and Lindsey Raymond, an AI assistant raised issues resolved per hour by 14% on average. Novice and low-skilled agents improved by 34%. Experienced agents saw minimal impact. The authors also reported better customer sentiment and staff retention.
That pattern matters for measurement. Averages hide where the gain sits. Track results by experience level and by request type, and a workflow that looks modest overall may turn out to be lifting new starters sharply.
Useful operations measures:
- Throughput: requests or reports completed per person per week.
- Time to approved work: from request complete to sign-off.
- Rework rate: share of outputs sent back for correction.
- Consistency: whether different people give customers the same facts.
What does AI ROI look like in finance?
Finance returns come from faster preparation and earlier error-spotting: drafting management report commentary, checking documents against a standard, summarising contracts against a checklist. Measure close time, errors caught before sign-off and outside spend avoided. Keep a person approving every number, because accuracy matters more here than speed.
Finance is where the gap between fluent and correct matters most. In BCG's 2023 experiment with 758 of its consultants, those using GPT-4 performed 40% better on creative product tasks. On a business problem-solving task outside the tool's strengths, however, they performed 23% worse than colleagues without it. Confident output on the wrong task is a finance risk.
So design finance workflows around checking. AI prepares, highlights and drafts. A person verifies, approves and owns the figure. Nothing is spent or reported on AI output alone.
How do you compare AI ROI across functions fairly?
Use the same formula everywhere: net benefit divided by full cost, per workflow, over the same review period. Let each function supply its own measure and baseline. Compare workflows on payback and confidence in the data, not on headline percentages, because small baselines make percentages look dramatic.
A fair comparison has four rules:
- Per workflow, not per department. A department is a mix of good and bad workflows.
- Same period. Quarterly reviews for everyone, with the same baseline length.
- Full cost. Setup, review time and upkeep, not just licences.
- Data confidence. Mark each result as system-measured or estimated, and weight accordingly.
The broader method sits in the guide to where AI pays first, which ranks candidate workflows before any money moves.
Skein measures outcomes such as pipeline, cost per lead, time to first draft, AI visibility, search demand won and adoption, choosing the measure that fits each workflow; the outcomes page lists them. That suits a business running AI in more than one team that wants returns compared on the same terms. A business using AI in a single team can skip the cross-function view and measure that team well.
Frequently asked questions
Which department gets the best ROI from AI?
It varies by business, but evidence often points to back-office work such as support, reporting and document checks, where tasks are frequent and measurable. MIT NANDA's research, as reported by Fortune, found the largest returns in back-office automation even though most budgets go to sales and marketing tools.
How do you measure AI ROI in sales?
Measure meetings booked per rep, time from call to follow-up, proposal win rate and pipeline per rep, each against a baseline from before AI. Avoid judging on emails sent or activity counts. Make sure the CRM records outcomes reliably, and keep a person approving anything sent to a prospect.
How do you measure AI ROI in marketing?
Track time to first draft for speed, then cost per lead, booked-call rate and pipeline for return. For organic work, add AI visibility and search demand won. Judge marketing AI on booked calls and pipeline rather than content volume, and give deals a full sales cycle to show.
Can AI improve finance team productivity?
Yes, mainly by preparing report commentary, checking documents against a standard and summarising contracts, which shortens preparation time and catches errors earlier. Keep a person verifying and approving every figure, because AI can be confidently wrong on tasks outside its strengths, and finance errors are costly.
How do you compare AI ROI between departments?
Use one formula, net benefit divided by full cost, per workflow and over the same review period. Let each function use its own measure and baseline. Compare on payback and data quality rather than headline percentages, which look dramatic when the starting baseline is small.
Related reading
- Estrada, Sheryl. "MIT report: 95% of generative AI pilots at companies are failing." Fortune, 18 August 2025, via Yahoo Finance. https://finance.yahoo.com/news/mit-report-95-generative-ai-105412686.html
- MIT News. "Study finds ChatGPT boosts worker productivity for some writing tasks." MIT, 14 July 2023. https://news.mit.edu/2023/study-finds-chatgpt-boosts-worker-productivity-writing-0714
- Brynjolfsson, Erik, Danielle Li and Lindsey Raymond. "Generative AI at Work." NBER Working Paper 31161, 2023; Quarterly Journal of Economics, 2025. https://www.nber.org/papers/w31161
- BCG. "How People Can Create and Destroy Value with Generative AI." BCG, 21 September 2023. https://www.bcg.com/publications/2023/how-people-create-and-destroy-value-with-gen-ai