The AI Agent Marketplace ROI Calculator
The spreadsheet that gets leadership to say yes.
Audience: Engineering managers, VPs, CTOs
Why You Need This
The #1 blocker for marketplace adoption isn't technology. It's a VP asking "what's the ROI?" and getting a shrug. This guide gives you a concrete model to quantify the value.
The ROI Model
Inputs (fill in your numbers)
| Input | Description | Example Value |
|---|---|---|
E |
Number of engineers in your org | 200 |
H |
Average hourly cost (salary + benefits + overhead) | $85/hr |
D |
Average days to onboard a new hire (productive coding) | 30 days |
P |
PRs reviewed per engineer per week | 5 |
I |
Incidents per month | 12 |
T_triage |
Average time to triage an incident (minutes) | 45 min |
T_review |
Average time for a thorough code review (minutes) | 30 min |
T_test |
Average time to write tests for a feature (hours) | 3 hrs |
D_dup |
Estimated % of AI agent work that's duplicated across teams | 30% |
Cost of Doing Nothing (Annual)
| Cost Category | Formula | Example |
|---|---|---|
| Duplicated agent work | E * 2hrs/month * 12 * H * D_dup |
200 * 2 * 12 * \(85 * 0.3 = \)122,400 |
| Inconsistent code quality | P * E * 5min/PR * 52weeks * H/60 |
5 * 200 * 5 * 52 * \(1.42 = \)369,200 in review overhead |
| Slow incident response | I * T_triage * 12 * H/60 * 3 engineers |
12 * 45 * 12 * \(1.42 * 3 = \)27,648 |
| Extended onboarding | new_hires * 5days_saved * 8hrs * H |
40 * 5 * 8 * \(85 = \)136,000 |
| Knowledge loss (attrition) | departures * 40hrs_lost * H |
30 * 40 * \(85 = \)102,000 |
| Total annual cost | ~$757,000 |
Cost of the Marketplace (Annual)
| Investment | Estimate |
|---|---|
| Initial setup (1 platform engineer, 2 weeks) | $6,800 |
| Seed 5 plugins (5 engineers, 1 day each) | $3,400 |
| Ongoing maintenance (0.25 FTE) | $44,200 |
| AI tool licenses (already paying for these) | $0 incremental |
| Total annual cost | ~$54,400 |
ROI Calculation
Net Value = Cost of Doing Nothing - Cost of Marketplace
= \(757,000 - \)54,400
= $702,600
ROI = Net Value / Cost of Marketplace
= \(702,600 / \)54,400
= 12.9x return
Payback = Cost of Marketplace / (Net Value / 12 months)
= \(54,400 / \)58,550
= < 1 month
Your mileage will vary. These numbers are illustrative. The point is to give you a framework to plug in YOUR numbers and present to leadership.
Beyond Dollars: Metrics That Matter
Financial ROI gets the initial "yes." These metrics sustain long-term support:
Developer Experience Metrics
| Metric | How to Measure | Target |
|---|---|---|
| Time to first contribution | Days from marketplace launch to first external plugin PR | < 30 days |
| Plugin adoption rate | % of repos with at least one marketplace plugin installed | > 50% in 6 months |
| Repeat usage | % of installers who install a second plugin | > 60% |
| Developer NPS | "Would you recommend the marketplace to a colleague?" (0-10) | > 40 |
Quality Metrics
| Metric | How to Measure | Target |
|---|---|---|
| Security findings per PR | Automated catches from marketplace security rules | Track trend (should increase then plateau) |
| Incident MTTR | Mean time to resolve with vs. without marketplace plugins | 20% reduction |
| Test coverage delta | Coverage change in repos after test-writer adoption | +10% average |
| Onboarding time | Days to first meaningful PR for new hires | 30% reduction |
Ecosystem Health Metrics
| Metric | How to Measure | Target |
|---|---|---|
| Total plugins | Count in marketplace | 10+ in 6 months |
| Active contributors | Unique authors of merged plugin PRs per quarter | 5% of engineering org |
| Plugin freshness | % of plugins updated in last 90 days | > 70% |
| Cross-team reuse | Plugins used by 3+ teams | > 50% of plugins |
How to Present This to Leadership
The One-Slide Pitch
PROBLEM: 200 engineers using AI tools independently = chaos
30% duplicated work, zero governance, knowledge silos
SOLUTION: Internal AI Agent Marketplace
Shared plugins, org-wide rules, built-in compliance
COST: ~$54K/year (0.25 FTE + 2-week setup)
VALUE: ~$700K/year in recovered productivity
+ Consistent code quality across all teams
+ Compliance by default (not by audit)
+ Institutional AI knowledge that survives attrition
ASK: 1 platform engineer for 2 weeks
Then 25% of their time ongoing
ROI: 12.9x return, payback in < 1 month
The Three Questions You'll Get
"Can't we just write a wiki page with prompts?" A wiki is where prompts go to die. Nobody discovers them, nobody updates them, and there's no governance. The marketplace has a CLI (marketplace browse), version control, automated testing, and telemetry. It's the difference between a Google Doc of recipes and a restaurant kitchen.
"We already have GitHub Copilot / Claude / Cursor licenses. Isn't that enough?" Those tools are the engines. The marketplace is the fuel. Without shared rules and skills, each engineer drives in a different direction. The marketplace aligns them without taking away their choice of vehicle.
"What if engineers don't contribute?" They will, if consuming is easy. The contribution flywheel starts with consumption: install a plugin, find it useful, notice a gap, submit a PR. Your first 5 plugins come from the platform team. The next 50 come from the engineers who used those 5.
Template: Quarterly Business Review
Use this template to report marketplace impact quarterly:
## AI Agent Marketplace: Q[X] Review
### Adoption
- Plugins available: [N] (up from [N-1])
- Repos with marketplace installed: [N] / [Total] ([%])
- Monthly active plugin installs: [N]
- Unique contributors this quarter: [N]
### Impact
- Estimated engineering hours saved: [N] hrs
- Security findings caught by marketplace rules: [N]
- Average incident MTTR with marketplace: [N] min (down from [N] min)
- New hire onboarding time: [N] days (down from [N] days)
### Top Plugins by Usage
1. [plugin-name]: [N] installs, [N] active repos
2. [plugin-name]: [N] installs, [N] active repos
3. [plugin-name]: [N] installs, [N] active repos
### What's Next
- [Planned plugin or initiative]
- [Planned plugin or initiative]
This is a bonus post in the AI Agent Marketplace series.
