Judge the rise on whether the customers who saw it kept buying, at 90 and 180 days, against a comparison. Conversion rate is a guardrail, not a verdict.
The week after a rise, someone will read the conversion rate and declare victory or defeat. Both are premature. New visitors have no reference price. The stock-up window moves orders around the date. And customers who leave over price just don’t come back: in Anderson and Simester’s experiment the lost orders showed up over 28 months Published.
You need something to compare with, decided before the rise. Three workable options, best first:
Randomly holding some customers at old prices gives the cleanest answer, and creates what chapter 9 warns about: two customers paying different prices. If you do it, keep the group small, give it an end date, and have counsel review it. The Honest Test covers price tests.
| Number | Defined as | When | What it catches |
|---|---|---|---|
| Volume against break-even | Units per SKU, four-week average after the stock-up window, against break-even (chapter 3) | Weekly | A rise losing more than it can afford |
| Contribution per SKU | Monthly contribution against the same months before | Monthly | Whether the rise earns what it should |
| 90-day repeat rate | Share of customers active before the rise who reordered within 90 days, against the comparison | Day 90 | The early read on existing customers |
| 180-day repeat rate | The same, at 180 days | Day 180 | The verdict |
| Subscriber survival | Share active through the first two renewals at the new price | Each renewal | Subscribers leaving quietly |
| Price cancellations and tickets | Cancellations and tickets citing price, per 1,000 orders | Weekly | A story that isn’t landing |
| Tier mix | Share of orders in each tier | Weekly | Buyers sliding down the ladder (chapter 7) |
| New-customer conversion and first-order value | Against the four weeks before | Weekly | A guardrail on acquisition, not the verdict |
Conversion tells you how strangers took the price. Retention tells you how your customers took the rise.
At 90 days, compare each SKU’s volume loss with its break-even and the repeat rate with the comparison. Volume loss well inside break-even and a repeat rate close to the comparison is a rise that worked; confirm it at 180 days. If repeat rate falls further behind than the break-even allows, the fix is usually in chapter 9 or chapter 10, not a price cut. Rerun the tool in chapter 8 with the loss you saw before the next rise.
This is one chapter of The Price Rise, which is free and readable in full on a single page with no form in front of it.