None of this needs new software: a survey, three queries, a holdout flag in your email platform and one scoring meeting. Here’s the order.

1. Week 1 · Measure the coreScore the audit in chapter 1. Send the share-of-wallet survey to active customers. Pull core revenue per active customer for three years. Run the headroom calculator with whatever you have, and update it when the survey closes.
2. Week 2 · Correct the numbersRebuild the multi-category comparison with an early window (chapter 7). Compute contribution per cross-buyer and build the “no cross-sell” segment (chapter 8). Add a 10% holdout to your main cross-category flow (chapter 10). Check goals and bonus plans for category-count targets (chapter 9).
3. Week 3 · Score the candidatesScore every candidate on the four shared things in one meeting (chapter 4). Send the fit survey on the top three (chapter 5). For anything two or more steps out, list complementors and contact one (chapter 12).
4. Week 4 · DecidePut headroom next to the best candidate’s break-even. If the core is the bigger opportunity, the next quarter goes to moving customers up a rank. If the candidate wins, write the launch brief with its repeat bar and kill rule, and open the waitlist to the base (chapter 11).

At the end of the month you’ll have a share-of-wallet number, an honest multi-category multiple, a list of cross-buyers who cost money, a running holdout and a scored shortlist.

Do this

• Put the four weeks in the calendar today, with one owner, and move the next launch’s stock order to after week 4.