ROI Is a Shared Lie

Early in my career I learned that ROI isn’t just a number—it’s a story we build together. When I wrote about this in Being Wrong to Be Right, I described a meeting where a CIO challenged my initial value estimate, and together we rebuilt it line by line. What started as me being wrong turned into one of the most productive, trust-building discussions of my career.

That conversation taught me something profound: it’s not about being 100% accurate—it’s about being believably accurate. The number itself is less important than the shared understanding that built it.

In many sales conversations we push ROI calculators, dashboards, and “here’s our model” slides as if the guarantee is in the digits. But what matters more is whether the customer buys the logic of the model, sees themselves in it, and agrees with the assumptions—not whether we nailed every decimal place.

It’s Less About Accuracy, More About Alignment

Imagine you present a 5-year savings model to a CFO, rooted in your assumptions. You show cost avoidance, improved efficiency, maybe revenue uplift. Technically, it might be solid. But if the CFO looks at it and thinks: “I don’t agree with your assumptions, I don’t trust your inputs, I don’t see this in my world,” then you’ve simply handed over a polished spreadsheet—not a believable story.

In contrast, when you invite the customer into the model—“Here’s my starting assumption, let’s walk it through together”—you shift from presenting to collaborating. That’s what builds ownership. That’s what transforms ROI from a slide into a shared lie you both agree to believe.

The best value conversations follow a rhythm. You present your logical estimate, they correct your numbers, you update the model together, and in the process you both end up believing the outcome. It’s not that anyone is trying to deceive; it’s that you’re building a mutually accepted truth. When the CFO later asks, “Where did these numbers come from?” the customer champion can proudly respond, “They’re our numbers.”

That’s the goal—not perfection, but alignment.

Why We Keep Pretending It Has to Be Perfect

We chase precision because it feels safe.

• We fear being wrong, so we hide behind decimal places.
• We think credibility comes from detail instead of direction.
• We assume the buyer values accuracy more than ownership.

But the buyer doesn’t need your spreadsheet to be perfect—they need to trust it enough to defend it internally. They want logic they can explain and assumptions they can repeat. If they can’t restate your value model in their own words, it isn’t believable.

And that’s where so many deals go wrong. We build complex ROI models full of compound calculations, risk adjustments, and obscure formulas. It might impress a financial analyst, but it alienates everyone else.

ROI has to be human-readable. It should fit on a single page. The best ROI models start with simple math that makes sense at a glance. You can always refine the numbers later, but if the logic isn’t obvious and explainable, you’ve already lost the argument.

Anchor ROI to What the Business Measures

Even a logical, simple ROI model fails if it isn’t tied to what the business actually measures. Every value story must anchor to one of four things:

1. Revenue – Does this create or accelerate income? Can it shorten time-to-market or increase average deal size?
2. Cost – Does it reduce operating expenses, streamline labor, or lower maintenance costs?
3. Risk – Does it minimize compliance exposure, reputational damage, or downtime?
4. Mission or KPI Alignment – Does it advance the organization’s stated goals? For example, improving sustainability metrics, customer satisfaction scores, or speed of innovation.

If your ROI doesn’t align to one of these categories, it’s not grounded in business reality—it’s just math.

This is where collaboration pays off. When you build the model together, your customer will naturally push you toward what actually matters to them. You might start by talking about efficiency, but they’ll quickly steer you toward the KPI their bonus depends on. That’s when you know you’re on the right track.

From Shared Hypothesis to Shared Value

Here’s how to make ROI a shared lie worth believing:

1. Start with a hypothesis. Offer your best guess based on available data. Don’t wait for perfect inputs—your job is to start the story.
2. Show the math, not the magic. Keep calculations simple enough for the customer to follow in real time. The goal is clarity, not complexity.
3. Walk through each assumption out loud. Explain how you arrived at the number. Make it transparent and defensible.
4. Ask, “What should we change?” That question transforms the conversation from justification to collaboration.
5. Update the model together. The more they participate, the more ownership they feel.
6. Anchor the ROI to outcomes, not math. Tie the result to tangible business drivers—cost, risk, or revenue. Numbers only matter when they support a meaningful outcome.
7. Close the loop. When the model is done, say, “Can you explain this back to me in your words?” If they can, you’ve reached shared belief.

Practical Exercise: Build a Shared ROI

1. Choose an active opportunity and outline your initial ROI estimate in three lines or less.
2. List every assumption that drives those numbers.
3. Meet with your champion and review only the assumptions. Ask, “What should we change?”
4. Adjust the model together, keeping math simple and logical.
5. Write one sentence that summarizes the shared story in their language—“This investment allows us to avoid $250K in risk and launch two additional products this year.”

Repeat this process until you both can tell the same story without the spreadsheet. That’s when the number stops being yours—and starts being ours.

Why This Matters

ROI isn’t a test of accuracy; it’s a test of agreement. The number doesn’t have to be perfect—it just has to be believable, explainable, and shared.

When your customer owns the logic, they also own the justification. They defend it to leadership because it’s their truth, not yours.

ROI is a lie until you make it real with your customer—then it becomes a shared lie.

And that’s the moment ROI stops being a report—and becomes a reason to buy.