A SaaS company can grow revenue 40% year over year while quietly losing money on every new customer it acquires. Revenue growth, taken alone, can't distinguish between a business that's compounding sustainably and one that's spending its way to a larger top line. LTV:CAC ratio is one of the core numbers built specifically to catch that difference.
What the ratio actually compares
Customer Lifetime Value (LTV) estimates the total revenue a customer generates over their relationship with the business; Customer Acquisition Cost (CAC) is what it cost in sales and marketing spend to acquire them. The ratio between the two answers a simple question: for every dollar spent acquiring a customer, how many dollars does that customer return over time.
What counts as healthy
A commonly cited benchmark is an LTV:CAC ratio of 3:1 or higher — three dollars of lifetime value for every dollar spent acquiring the customer. Below that, and the economics of growth start to look strained; well above it (particularly much higher than 5:1) can sometimes signal under-investment in growth rather than unusual efficiency.
Why CAC Payback Period is the companion number worth tracking too
LTV:CAC tells you about the ratio over a customer's full lifetime, but it doesn't say anything about cash flow timing. CAC Payback Period — how many months it takes to recover the acquisition cost through that customer's revenue — matters separately, because a business can have a strong LTV:CAC ratio on paper while still running into a cash crunch if payback takes too long relative to how fast it's acquiring new customers.
Why logo churn and revenue churn need to be tracked separately
A business can have flat logo churn (the same number of customers leaving) while revenue churn worsens, if the customers leaving are disproportionately larger accounts — or the reverse, losing many small accounts while revenue stays stable. Tracking both separately, not just a blended churn number, shows which story is actually happening.