Payback period

Payback period is the number of months it takes for the gross margin from new customers to repay what you spent acquiring them. Most teams track it as CAC (customer acquisition cost) payback: sales and marketing spend on new customers, divided by the monthly gross margin those customers bring in. A shorter payback means your cash comes back sooner and can be spent again.

How to measure it

Payback period (months) = sales and marketing spend on new customers ÷ (new monthly recurring revenue from those customers × gross margin percentage)

Benchmarkit defines it as how many months it takes to "payback" the Sales and Marketing Expenses for new customers, on a gross margin adjusted basis. Run the calculation per channel and per monthly cohort of new customers.

A concrete case

Take a paid acquisition loop. The faster each cohort pays back, the sooner that cash funds the next round of spend. In that author's words, this lets you increase the speed at which the Growth Loop cycle completes. Our guide to growth loops covers how the loop is built.

For a reference point, Benchmarkit notes that common wisdom often says ~12 months CAC Payback Period is good. It also reported that the metric is highly correlated to ACV (annual contract value). It found that CAC Payback Period has increased 12.5% at median since 2022.

Usual mistakes

• Using revenue instead of gross margin. Payback will look shorter than it really is.
• Comparing against one rule of thumb. Small contracts and large contracts pay back on different clocks. Compare yourself with companies at a similar contract size.
• Blending channels. An average across organic and paid can hide a paid channel that never earns its spend back.
• Ignoring churn. If customers cancel before the payback month, the spend is never recovered. Check your numbers against monthly churn benchmarks.
• Treating it as the full picture. Benchmarkit notes it does not provide the granularity of CAC efficiency provided by the CAC Ratio.

When it matters

It matters most when you are deciding whether to put more money into a paid channel, or when cash is short. This week, pull last quarter's spend and new revenue for each channel. Calculate payback per channel and cut or cap the channels that recover their spend slowest.