Part one · Count what breaks · Chapter 2

WHAT A BROKEN PROMISE COSTS

The refund and the reship are the small part. The large part is the next order that never comes, and you can measure it on your own store.

Ask a team what a late order costs and they’ll add up the credit, the agent’s time and maybe a reship. The cost they can’t see is the customer who quietly orders less often afterward. It shows up months later, in a cohort report nobody connects to the day the package was late.

What the research finds

Two details matter later. Harter’s team, and a study of ratings at a South American online retailer by Serkan Akturk and colleagues, both found that the damage from lateness grows more slowly as the delay gets longer Published. The first day late does a large share of the harm, which makes the promised date in chapter 4 the cheapest lever in this guide. And Norvell’s result previews chapter 10: recovery softens a failure but doesn’t erase it.

A late order doesn’t cost you a refund. It costs you part of the next order, and the one after that.

Measure it on your own store

Studies give the direction. Your own data gives the size, and the size wins budget. The method is a failure cohort:

  1. Take first-time customers from a full year agoSo everyone has had twelve months to come back.
  2. Label what happened to that first orderOn time, late 1 to 2 days, late 3 or more, wrong or missing, damaged, lost, split without warning. One label per order, the worst.
  3. Compare repeat rates within matched groupsLate orders cluster in far regions and peak weeks. Compare within the same month, region and first product.
  4. Read the gap, with its uncertaintyPool quarters until each group has a few hundred customers.

Matching narrows the bias without removing it. The cleanest evidence comes from failures you didn’t choose, like a carrier’s regional outage: customers caught in it were failed more or less at random. Keep a dated list of such events. The query is in Appendix A.

A worked example

Say a brand ships 10,000 orders a month and 6% of them fail in some way: 600 orders. Customers with no failure come back within a year at 30%. The failure cohort shows that a failure cuts that rate by a fifth, to 24%. So of the 600 failed customers, 36 who would have come back don’t. Each returning customer places 2.5 more orders in the year, at $25 of contribution each.

That’s 36 × 2.5 × $25 = $2,250 of contribution lost each month, from one month’s failures, before any refund or reship. At $12 of direct cost per failure, the direct cost is $7,200 a month. The hidden cost is almost a quarter of the total, and it’s the quarter nobody reports Derived.

Run your numbers

What does a broken promise cost?

Example numbers. Replace with yours. A failure is any order that was late, wrong, damaged, lost or split without warning.
repeat customers lost per month of failures
total cost per failure
of that cost is lost repeat contribution
a year, at this failure rate
a year, for each point of failure rate you remove
Lost repeat contribution per failure = repeat rate × relative drop × orders per returning customer × contribution per order. It counts only the first year after the failure and ignores word of mouth, so it’s a floor, not an estimate of the whole cost.

With the defaults, each failure costs $15.75, 24% of it in lost repeat contribution, and one point off the failure rate is worth about $18,900 a year. The 20% drop is a placeholder; replace it from your failure cohort, since it decides the answer. For scale, the Uber study’s 5% to 10% fall in spending followed a car ride that arrived late; a damaged or lost order is a bigger failure than that.

Do this

This is one chapter of The Kept Promise, which is free and readable in full on a single page with no form in front of it.