The go-to-market numbers founders should actually track

Ad platforms report the cost they can see. Real customer acquisition cost includes agency retainers, creative production, sales salaries and commission, the tooling that supports the funnel, and the discounts and refunds that never appear in the ad account. Building CAC from the ledger instead of the dashboard often changes the figure substantially, and it is the ledger version an investor will test.

The same applies to revenue. Gross sales, platform commission, payment fees, refunds and delivery all sit between the order and the money you keep, so a channel that looks profitable on revenue can lose money on contribution.

Customer acquisition cost: total sales and marketing cost for the period divided by new customers acquired. Report it blended and by channel.

CAC payback: acquisition cost divided by monthly gross-margin contribution per customer, expressed in months. Recovering it within twelve months is a common benchmark for UK subscription businesses.

Contribution margin: revenue less payment fees, delivery, refunds, platform commission, cost of goods and direct support or hosting cost per customer.

Net revenue retention: revenue from a cohort this period against the same cohort a year earlier, including expansion and contraction. Above 100% means the existing base grows without new sales.

Burn multiple: net cash burned divided by net new annual recurring revenue added, how much cash each pound of new revenue costs.

A monthly pack that ties these metrics to the management accounts beats a dashboard nobody trusts. The test is whether the pack ends with a decision: raise price on this plan, stop this channel, bring this hire forward, extend runway by delaying that spend.

Keep definitions written down and stable. Changing how CAC is calculated between board meetings destroys the trend, which was the only reason to measure it.

Thresholds, rates and deadlines quoted here reflect the 2026/27 UK position. Check current GOV.UK guidance, or ask us, before you rely on them for your own company.