Lead with the forecast you'd defend, label it a forecast, and staple the holdout to it.
Open your budget ask with a count of customers who bought once. Add what a second order is worth and a table of forecast rates, and hold the word retention for later. Budget moves when one number sits beside another and the gap is hard to ignore. Do the arithmetic in public, slowly enough that finance can check every line.
Three inputs, and only three. Two come from the order export; the third is an assumption and says so.
Incremental means reorders among the people you mailed, minus reorders in a holdout you didn't. A platform-attributed rate also counts people who'd have come back anyway, so a table built on it runs high.
Build this table for your founder, and show all five rows.
| Incremental rate (treated minus holdout), forecast | Customers recovered | Revenue (forecast) | What it takes |
|---|---|---|---|
| 5% | 676 | $60K | A bare email reactivation flow |
| 10% | 1,353 | $120K | A standard winback program, run well |
| 15% | 2,029 | $181K | Winback plus SMS (costs more per contact) |
| 20% | 2,705 | $241K | Multi-touch plus paid retargeting (costs more) |
| 25% | 3,382 | $301K | Best in class, deep personalization |
Forecast scenarios, not results. Base: 13,526 one-time buyers × the $89 step-up. Your base is the one-time buyers you can lawfully and safely mail. Count them before you price them; on a six-year file it will be well under the total. With a 10% holdout, 12,173 people are contacted, so multiply by 0.9. No allowance for the discount on the reactivating order: it comes out of the step-up.
At an assumed all-in $5 a contact, $67,630 across 13,526 people, the 10% forecast returns about 1.8 times its cost in revenue, before product cost and discount. The 5% row doesn't cover it. Break-even on revenue sits near a 5.6% rate.
You'll want to lead with the 25% row. Don't. Point at the 10% row and say: "This is an assumption, not a result. It's the row I'd defend. Everything above it is upside I'm not asking you to fund."
Lead with 25% and you spend twenty minutes defending a number you have no data for. Lead with 10% and the question gets simple: can the program run for a few dollars a contact, all in? An email program can; the offer is the real cost. The holdout will tell you which row you landed in. The ceiling starts a fight about optimism. The row you'd defend starts a decision.
The $89 is the gap between customers who came back on their own and customers who didn't. Customers you win back with an offer land below it, because the discount comes out of the step-up. So label every row a forecast, and subtract the offer before the slide goes out.
The first time a program beats its forecast, everything else on the slide becomes credible. The first time it misses, nobody believes the slide again.
Once the inputs exist, say something close to this.
"You have [count] customers who bought once. On your own file, net of refunds, a customer who orders again is worth [step-up] more. I am not asking for a retention budget. I am asking for [amount] to go after the 10% row, labeled forecast. I'll hold back a no-send group from day one, so you can see whether it worked without taking my word for it."
Every clause does a job. The count and the step-up come from the founder's own file, so there's nothing to take on trust. The 10% carries its label, which makes it believable. The holdout is an offer to be proven wrong. Make it before they ask. Keep lifetime value and loyalty out of the meeting: both are true, and neither has a price tag.
A retention budget that's one number gets cut as one number. Split it.
Finance can argue with each line. It can't say you hid one.
Finance will say the attributed number overstates the program, and they're right. Concede it before they raise it: "Some of these people would have reordered anyway. The holdout design, the group size and the read date are on this page." The holdout mechanics are in Attribution Isn't Proof.
Conceding first removes the one serious objection, and it shows you know where your own numbers are soft. A finance team that watches you flag the weak spot gives you more room on the rest of the case.
Promise a measured read on a named date: incremental revenue per profile, treated against holdout, by the method agreed that day. Promise the work: the flows, the segments, the data fixes. Never promise a number. Say it out loud: no honest operator sells a guaranteed lift. Treat any guaranteed percentage as a sales number, not a forecast.
Refuse the guarantee, offer a method and a date instead, and you're offering the one thing an attribution report can't. Ask for a bounded amount over a set window, sized so the holdout can return a readable answer. A budget too small to read buys an inconclusive result and a harder second conversation.
Count the one-time buyers you can lawfully mail. If the 10% row on that count won't pay for the people and tools on your first budget line, fold reactivation into your existing flows and skip the separate ask.
This is one chapter of The Second Order, which is free and readable in full on a single page with no form in front of it.