The decisions Shopify founders actually face
Most Shopify founders have a strong instinct for the top of the funnel and weaker instincts for what happens after the order is placed. The gross margin in the Shopify dashboard is a starting point, not the answer. By the time an order is fulfilled, returned at the typical category rate, hit with payment processing fees, allocated a fair share of the day's paid acquisition, and charged a fair share of platform fees and apps, the true contribution margin per order is often ten to twenty points lower than the Shopify number.
The job of a fractional CFO for a Shopify brand is to make that real number visible at the channel level, the SKU level, and the cohort level, and to use it to decide where the next £1 of marketing spend goes.
The Shopify-specific stack
Shopify brands tend to run on a fairly consistent stack: Shopify for orders, a 3PL or Shipbob for fulfilment, Klaviyo for email and SMS, one or two paid channels (Meta, Google, TikTok), a returns platform like Loop, a payment processor (Shopify Payments, Stripe), a subscription app for repeat orders, and an attribution tool layered on top. Each one produces data, and almost none of it reconciles natively to Xero or QuickBooks without intermediation.
The fractional CFO's job here is to set up the reconciliation cleanly (A2X is usually the cleanest answer), agree the source of truth for each KPI, and then make the data usable rather than impressive.
The two numbers we watch hardest
For most Shopify brands, two numbers determine the next twelve months. The first is blended CAC payback in months: how long, on a contribution-margin basis, until the average new customer has paid back what it cost to acquire them. Below six months at scale is healthy; above twelve months is dangerous regardless of LTV claims. The second is the cash conversion cycle: the gap between paying a supplier for stock and collecting payment from the customer who eventually buys it. For most Shopify brands this is dominated by stock, not by receivables, and is the binding constraint on how fast the brand can grow.