A working ecommerce advisory diagnostic is a 25 to 40 page document that lands in week 2 or week 3 of the engagement. It covers six sections in order: current-state operating metrics, channel-by-channel contribution analysis, retention and cohort behavior, contribution margin by SKU, structural problems blocking growth, and a prioritized initiative pipeline.
Current-state operating metrics. Blended CAC, contribution-margin LTV at 24 months, payback period in months, gross margin, contribution margin per order, returning-customer rate at 90 days, average order value, conversion rate by template (homepage, product, collection, cart, checkout), and Core Web Vitals at the 75th percentile per web.dev. Each metric carries a 30-day, 90-day, and 12-month figure so the advisor can identify trend versus snapshot.
Channel-by-channel contribution analysis. Meta, Google, TikTok, email, organic, affiliate, partnerships - each channel gets a contribution-margin ROAS figure with proper customer-level deduplication. Most operators look at platform-reported ROAS in Shopify's marketing attribution view or in their ad platform native dashboards, and platform-reported ROAS is gameable. The diagnostic uses customer-level data joined back to acquisition source, deduplicated against returning customers, and the contribution-margin figure rather than the revenue figure.
Retention and cohort behavior. A 24-month cohort table showing repeat-purchase rate, contribution-margin LTV, and time-to-second-purchase by acquisition month. The cohort table is where the diagnostic identifies whether the brand has a retention problem (most $1M to $10M operators do) or a top-of-funnel problem. A flat cohort curve plus low blended CAC means top-of-funnel is fine and retention is the load-bearing initiative; a steep cohort curve plus high blended CAC means top-of-funnel is broken and the retention work is premature.
Contribution margin by SKU. The top 20 products by gross revenue plus the bottom 20 by gross revenue, each with their contribution margin, returns rate, and inventory velocity. Most $1M to $10M operators discover at least two SKUs in the top 20 by revenue that have negative or near-zero contribution margin once shipping, returns, and payment-processing costs are accounted for - and these are usually the SKUs the brand is paying to acquire customers for. The diagnostic recommends pruning or repricing those SKUs, which usually shows up as the highest-impact single change in the first 90 days.
Structural problems blocking growth. The top three to five structural issues the diagnostic surfaces - typically a mix of platform constraints, retention mechanics, channel concentration, and team capability gaps. A real diagnostic names at least two structural problems the operator did not already know about, with a sized estimate of the revenue lift from solving each.
Prioritized initiative pipeline. Eight to twelve named initiatives ranked by expected revenue lift, effort in person-weeks, and elapsed time to results. Each has a named in-house owner, a target ship date, and the metric it will move on the dashboard. The pipeline is the bridge between the diagnostic and the rest of the quarter.
An advisory engagement that produces a thinner diagnostic - 8 to 15 pages, no SKU-level analysis, no cohort table - is selling generic strategy. The 25 to 40 page bar is not arbitrary; the analytical density is what separates real diagnostic work from a strategy deck.